The balance sheets at the end of each of the first two years of operations indicate the following: 2012 2011 Total current assets $615,855 $587,250 Total investments $61,771 $52,797 Total property, plant, and equipment $863,832 $713,042 Total current liabilities $105,168 $88,711 Total long-term liabilities $286,605 $248,684 Preferred 9% stock, $100 par $83,769 $83,769 Common stock, $10 par $531,322 $531,322 Paid-in capital in excess of par-common stock $66,746 $66,746 Retained earnings $467,848 $333,857 If net income is $115,568 and interest expense is $37,407 for 2012 what is the rate earned on stockholders' equity for 2012 (round percent to two decimal points)?