What is the Quality of Earnings for 2018, 2019, 2020? Please provide a brief explanation.

2020 42,122 42,274 23,795 24,542 132,733 113, 114 37,553 15,017 22,778 321,195 $s in Millions, except per share data December 31, 2018 2019 Assets Current assets: Cash and cash equivalents $ 31,750 $ 36,092 $ Marketable securities $ 9,500 $ 18,929 $ Inventories $ 17,174 $ 20,497 $ Accounts receivable, net and other $ 16,677 $ 20,816 $ Total current assets $ 75,101 $ 96,334 $ Property and equipment, net $ 61,797 $ 72,705 $ Operating leases $ 25,141 $ Goodwill $ 14,548 $ 14,754 $ Other assets $ 11,202 $ 16,314 $ Total assets $ 162,648 $ 225,248 $ Liabilities and Stockholders' Equity Current liabilities: Accounts payable $ 38,192 $ 47,183 $ Accrued expenses and other $ 23,663 $ 32,439 $ Unearned revenue $ 6,536 $ 8,190 $ Total current liabilities $ 68,391 $ 87,812 $ Long-term lease liabilities $ 9,650 $ 39,791 $ Long-term debt $ 23,495 $ 23,414 $ Other long-term liabilities $ 17,563 $ 12,171 $ Commitments and contingencies (Note 7) Stockholders' equity: Preferred stock, $0.01 par value: Authorized shares - 500 Issued and outstanding shares none Common stock, $0.01 par value: Authorized shares - 5.000 Issued shares - 521 and 527 Outstanding shares 498 and 503 $ 5 $ 5 $ Treasury stock, at cost $ (1,837) $ (1,837) $ Additional paid-in capital $ 26,791 $ 33,658 $ Accumulated other comprehensive income (loss) $ (1,035) $ (986) $ Retained earnings $ 19,625 $ 31,220 $ Total stockholders' equity $ 43,549 $ 62,060 $ Total liabilities and stockholders' equity $ 162,648 $ 225,248 $ 72,539 44,138 9,708 126,385 52,573 31,816 17,017 5 (1,837) 42,865 (180) 52,551 93,404 321,195 Fields using formulas Year Ended December 31, 2018 2019 2020 21,856 $ 32,173 $ 36,410 $ $ 10,073 $ 11,588 $ 21,331 $ $ $ $ $ 15,341 $ 5,418 $ 274 $ 219 $ 441 $ 21,789 $ 6,864 $ 164 $ (249) $ 796 $ 25,251 9,208 (71 (2,582 (554) $ $ $ $ $ $ (1,314) $ (4,615) $ 3,263 $ 472 $ 1,151 $ 30,723 $ (3,278) $ (7,681) $ 8,193 $ (1,383) $ 1,711 $ 38,514 $ (2,849) (8,169 17,480 5,754 1,265 66,064 CASH, CASH EQUIVALENTS, AND RESTRICTED CASH, BEGINNING OF PERIOD OPERATING ACTIVITIES: Net income Adjustments to reconcile net income to net cash from operating activities: Depreciation and amortization of property and equipment and capitalized content costs. operating lease assets, and other Stock-based compensation Other operating expense (income), net Other expense (income), net Deferred income taxes Changes in operating assets and liabilities: Inventories Accounts receivable, net and other Accounts payable Accrued expenses and other Uneamed revenue Net cash provided by (used in) operating activities INVESTING ACTIVITIES: Purchases of property and equipment Proceeds from property and equipment sales and incentives Acquisitions, net of cash acquired, and other Sales and maturities of marketable securities Purchases of marketable securities Net cash provided by (used in) investing activities FINANCING ACTIVITIES: Proceeds from short-term debt, and other Repayments of short-term debt, and other Proceeds from long-term debt Repayments of long-term debt Principal repayments of finance leases Principal repayments of financing obligations Net cash provided by (used in) financing activities Foreign currency effect on cash cash equivalents, and restricted cash Net increase (decrease) in cash, cash equivalents, and restricted cash CASH, CASH EQUIVALENTS, AND RESTRICTED CASH, END OF PERIOD $ $ $ $ $ $ (13,427) $ 2,104 $ (2,186) $ 8,240 $ (7,100) $ (12,369) $ (16,861) $ 4,172 $ (2,461) $ 22,681 $ (31,812) $ (24,281) $ (40,140) 5,096 (2,325) 50,237 (72,479 (59,611 $ $ $ $ $ $ $ $ $ $ 886 $ (813) $ 182 $ (155) $ (7,449) $ (337) $ (7,686) $ (351) $ 10,317 $ 32,173 $ 1,402 $ (1,518) $ 871 S (1,166) $ (9,628) $ (27) $ (10,066) $ 70 $ 4,237 $ 36,410 $ 6,796 (6,177) 10,525 (1,553) (10,642 (53) (1,104 618 5,967 42,377 Fields using formulas $ $ Year Ended December 31, 2018 2019 2020 141,915 $ 160,408 $ 215,915 90,972 $ 120,114 $ 170,149 232,887 $ 280,522 $ 386,064 $ Net product sales Net service sales Total net sales Operating expenses: Cost of sales Fulfillment Technology and content Marketting General and administrative Other operating expense (income), net Total operating expenses Operating income Interest income Interest expense Other income (expense), net Total non-operating income (expense) Income before income taxes Provision for income taxes Equity-method investment activity, net of tax Net income Basic earnings per share Diluted earnings per share Weighted-average shares used in computation of earnings per share: Basic Diluted $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ 139,156 $ 34,027 $ 28,837 $ 13,814 $ 4,336 $ 296 $ 220,466 $ 12,421 $ 440 $ (1,417) $ (183) $ (1,160) $ 11,261 $ (1,197) $ 9 $ 10,073 $ 20.68 $ 20.14 $ 165,536 $ 233,307 40,232 $ 58,517 35,931 $ 42,740 18,878 $ 22,008 5,203 $ 6,668 201 $ (75) 265,981 $ 363,165 14,541 $ 22,899 832 $ 555 (1,600) $ (1,647) 203 $ 2,371 (565) $ 1,279 13,976 $ 24,178 (2,374) $ (2,863) (14) $ 16 11,588 $ 21,331 23.46 $ 42.64 23.01 $ $ 41.83 487 $ 494 $ $ $ 500 510 500 $ 504 $ Fields using formulas 2020 42,122 42,274 23,795 24,542 132,733 113, 114 37,553 15,017 22,778 321,195 $s in Millions, except per share data December 31, 2018 2019 Assets Current assets: Cash and cash equivalents $ 31,750 $ 36,092 $ Marketable securities $ 9,500 $ 18,929 $ Inventories $ 17,174 $ 20,497 $ Accounts receivable, net and other $ 16,677 $ 20,816 $ Total current assets $ 75,101 $ 96,334 $ Property and equipment, net $ 61,797 $ 72,705 $ Operating leases $ 25,141 $ Goodwill $ 14,548 $ 14,754 $ Other assets $ 11,202 $ 16,314 $ Total assets $ 162,648 $ 225,248 $ Liabilities and Stockholders' Equity Current liabilities: Accounts payable $ 38,192 $ 47,183 $ Accrued expenses and other $ 23,663 $ 32,439 $ Unearned revenue $ 6,536 $ 8,190 $ Total current liabilities $ 68,391 $ 87,812 $ Long-term lease liabilities $ 9,650 $ 39,791 $ Long-term debt $ 23,495 $ 23,414 $ Other long-term liabilities $ 17,563 $ 12,171 $ Commitments and contingencies (Note 7) Stockholders' equity: Preferred stock, $0.01 par value: Authorized shares - 500 Issued and outstanding shares none Common stock, $0.01 par value: Authorized shares - 5.000 Issued shares - 521 and 527 Outstanding shares 498 and 503 $ 5 $ 5 $ Treasury stock, at cost $ (1,837) $ (1,837) $ Additional paid-in capital $ 26,791 $ 33,658 $ Accumulated other comprehensive income (loss) $ (1,035) $ (986) $ Retained earnings $ 19,625 $ 31,220 $ Total stockholders' equity $ 43,549 $ 62,060 $ Total liabilities and stockholders' equity $ 162,648 $ 225,248 $ 72,539 44,138 9,708 126,385 52,573 31,816 17,017 5 (1,837) 42,865 (180) 52,551 93,404 321,195 Fields using formulas Year Ended December 31, 2018 2019 2020 21,856 $ 32,173 $ 36,410 $ $ 10,073 $ 11,588 $ 21,331 $ $ $ $ $ 15,341 $ 5,418 $ 274 $ 219 $ 441 $ 21,789 $ 6,864 $ 164 $ (249) $ 796 $ 25,251 9,208 (71 (2,582 (554) $ $ $ $ $ $ (1,314) $ (4,615) $ 3,263 $ 472 $ 1,151 $ 30,723 $ (3,278) $ (7,681) $ 8,193 $ (1,383) $ 1,711 $ 38,514 $ (2,849) (8,169 17,480 5,754 1,265 66,064 CASH, CASH EQUIVALENTS, AND RESTRICTED CASH, BEGINNING OF PERIOD OPERATING ACTIVITIES: Net income Adjustments to reconcile net income to net cash from operating activities: Depreciation and amortization of property and equipment and capitalized content costs. operating lease assets, and other Stock-based compensation Other operating expense (income), net Other expense (income), net Deferred income taxes Changes in operating assets and liabilities: Inventories Accounts receivable, net and other Accounts payable Accrued expenses and other Uneamed revenue Net cash provided by (used in) operating activities INVESTING ACTIVITIES: Purchases of property and equipment Proceeds from property and equipment sales and incentives Acquisitions, net of cash acquired, and other Sales and maturities of marketable securities Purchases of marketable securities Net cash provided by (used in) investing activities FINANCING ACTIVITIES: Proceeds from short-term debt, and other Repayments of short-term debt, and other Proceeds from long-term debt Repayments of long-term debt Principal repayments of finance leases Principal repayments of financing obligations Net cash provided by (used in) financing activities Foreign currency effect on cash cash equivalents, and restricted cash Net increase (decrease) in cash, cash equivalents, and restricted cash CASH, CASH EQUIVALENTS, AND RESTRICTED CASH, END OF PERIOD $ $ $ $ $ $ (13,427) $ 2,104 $ (2,186) $ 8,240 $ (7,100) $ (12,369) $ (16,861) $ 4,172 $ (2,461) $ 22,681 $ (31,812) $ (24,281) $ (40,140) 5,096 (2,325) 50,237 (72,479 (59,611 $ $ $ $ $ $ $ $ $ $ 886 $ (813) $ 182 $ (155) $ (7,449) $ (337) $ (7,686) $ (351) $ 10,317 $ 32,173 $ 1,402 $ (1,518) $ 871 S (1,166) $ (9,628) $ (27) $ (10,066) $ 70 $ 4,237 $ 36,410 $ 6,796 (6,177) 10,525 (1,553) (10,642 (53) (1,104 618 5,967 42,377 Fields using formulas $ $ Year Ended December 31, 2018 2019 2020 141,915 $ 160,408 $ 215,915 90,972 $ 120,114 $ 170,149 232,887 $ 280,522 $ 386,064 $ Net product sales Net service sales Total net sales Operating expenses: Cost of sales Fulfillment Technology and content Marketting General and administrative Other operating expense (income), net Total operating expenses Operating income Interest income Interest expense Other income (expense), net Total non-operating income (expense) Income before income taxes Provision for income taxes Equity-method investment activity, net of tax Net income Basic earnings per share Diluted earnings per share Weighted-average shares used in computation of earnings per share: Basic Diluted $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ 139,156 $ 34,027 $ 28,837 $ 13,814 $ 4,336 $ 296 $ 220,466 $ 12,421 $ 440 $ (1,417) $ (183) $ (1,160) $ 11,261 $ (1,197) $ 9 $ 10,073 $ 20.68 $ 20.14 $ 165,536 $ 233,307 40,232 $ 58,517 35,931 $ 42,740 18,878 $ 22,008 5,203 $ 6,668 201 $ (75) 265,981 $ 363,165 14,541 $ 22,899 832 $ 555 (1,600) $ (1,647) 203 $ 2,371 (565) $ 1,279 13,976 $ 24,178 (2,374) $ (2,863) (14) $ 16 11,588 $ 21,331 23.46 $ 42.64 23.01 $ $ 41.83 487 $ 494 $ $ $ 500 510 500 $ 504 $ Fields using formulas