Presented here are summarized data from the balance sheets and income statements of Wiper, Inc.:

WIPER, INC.
Condensed Balance Sheets
December 31, 2017, 2016, 2015
(in millions)
	2017			2016			2015
Current assets	$	650		$	900		$	700
Other assets		2,750			2,050			1,750
Total assets	$	3,400		$	2,950		$	2,450
Current liabilities	$	500		$	800		$	700
Long-term liabilities		1,500			1,000			800
Stockholders' equity		1,400			1,150			950
Total liabilities and stockholders' equity	$	3,400		$	2,950		$	2,450

WIPER, INC
Selected Income Statement and Other Data
For the year Ended December 31, 2017 and 2016
(in millions)
	2017			2016
Income statement data:
Sales	$	3,300		$	2,900
Operating income		380			300
Interest expense		80			70
Net income		300			230
Other data:
Average number of common shares outstanding		44			42
Total dividends paid	$	50		$	30

Required:

a. Calculate return on investment, based on net income and average total assets, for 2017 and 2016. (Do not round intermediate calculations. Round your answers to 1 decimal place.)