how was the 2019 total net sales amount of $160,408 calcualted as well as the other total net sales number underneath of $120,114 for the year 2019?

USD (S) shares in Millions, Sin Millions Ended Dec 31, 2019 Dec 31, 2018 $ 280,522 $ 232,887 Dec 31, 2017 % $ 177,866 Total net sales Operating expenses: Cost of sales Fulfillment Technology and content Marketing General and administrative 165,536 40,232 35,931 18,878 5.203 139,156 34,027 28,837 13,814 4,336 111,934 25.249 22,620 10,069 3,674 Other operating expense (income), net Total operating expenses Operating income Interest income 201 265,981 14,541 832 296 220,466 12,421 440 214 173,760 4,106 202 (848) 346 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 (1,600) 203 (565) 13,976 (2,374) (14) (1,417) (183) (1,160) 11,261 (1,197) 9 (300) 3.806 (769) (4) tax Net income Basic earnings per share $ 11,588 $ 23.46 $ 10,073 $ 20.68 S 3,033 $ 6.32 Diluted eamings per share S 23.01 S 20.14 $ 6.15 Weighted average shares used in computation of earnings per share: Basic (in shares) 494 487 480 Diluted (in shares) 504 500 493 Net product sales $ 160,408 S 141,915 S 118,573 Total net sales Net service sales Total net sales $ 120,114 $ 90,972 $ 59,293