On January 1, 2017, Grouper Corp. purchased 4,500 shares of treasury stock. Other information regarding Grouper Corp. is provided as follows.

		2017		2016
Net income		$99,000		$89,000
Dividends on preferred stock		$27,200		$27,200
Dividends on common stock		$21,600		$21,600
Weighted-average number of common shares outstanding		45,000		52,000
Common stockholders equity beginning of year		$690,750		$520,000
Common stockholders equity end of year		$850,500		$676,000

(a) Compute return on common stockholders equity for each year. (Round answers to 1 decimal place, e.g. 15.2.)