Based on information provided, what is the rate of return on common stockholder's equity on March 31, 2015?

	March 31, 2014	March 31, 2015
Net income	350000	423500
Preferred dividends	0	0
Total stockholder's equity	4300000	5085000
Stockholder's equity attributable to preferred stock	0	0
Number of common shares outstanding	275464	192168