Kong Inc. reported net income of $270,000 during 2013 and paid dividends of $26,000 on common stock. It also has 10,000 shares of 6%, $100 par value cumulative preferred stock outstanding. Common stockholders' equity was $1,200,000 on January 1, 2013, and $1,600,000 on December 31, 2013. The company's return on common stockholders' equity for 2013 is: