How would I find the total return on assets and net return on assets ratios for years 2015/2016 from the provided information?

EXHIBIT 5 Fitbit, Inc., Consolidated Statements of Operations, 2014First Quarter 2017 (in thousands) First Quarter 2017 2016 2015 2014 Revenue $298,942 $2,169,461 $1,857,998 $745,433 Cost of revenue 180,643 1,323,557 956,935 387,776 Gross profit 118,299 845,884 901,063 357,657 Operating expenses Research and development 87,785 320, 191 150,035 54,167 Sales and marketing 91,174 491,255 332,741 112,005 General and administrative 30,746 146,903 77.793 33,556 Change in contingent consideration (7.704) Total operating expenses 209,678 958, 349 552,865 199,728 Operating income 191,379) (112,465) 348, 198 157.929 Interest income (expense). net 1,096 3,156 (1.019) (2,222) Other expense, net 533 14 (59,230) (15,934) Income before income taxes (89,750) (109,295) 287,949 139,773 Income tax expense (29,671) (6,518) 112,272 7.996 Net income $(60,079 $(102,777) $ 175,677 $131.777 EXHIBIT 6 Fitbit, Inc., Condensed Consolidated Balance Sheets, 2015-2016 December 31, 2016 December 31, 2015 Assets Current assets Cash and cash equivalents Marketable securities Accounts receivable, net Inventories Prepaid expenses & other current assets Total current assets Property and equipment, net $ 301,320 404,693 477,825 230,387 66,346 1,480,571 76,553 51,036 27,521 174,097 10.448 $1,820,226 $ 535,846 128,632 469,200 178,146 43,530 1,355,414 44,501 22,157 12,216 83,020 1,758 $1,519,066 Goodwill Intangible assets, net Deferred tax assets Other assets Total assets Liabilities, Redeemable Convertible Preferred Stock and Stockholders' Equity Current liabilities Accounts payable Accrued liabilities Deferred revenue Income taxes payable Total current liabilities Other liabilities Total liabilities Stockholders' equity Common stock & paid-in capital Accumulated other comprehensive income Retained earnings Total stockholders' equity Total liabilities and stockholders' equity $ 313,773 390,561 49,904 7,694 761,932 59,762 821,694 $ 260,842 200,099 44,448 2,868 508,257 29,358 537,615 859,368 1978) 140,142 998,532 $1,820,226 737,841 691 242,919 981,451 $1,519,066