Concord Inc. reported a net income of $284000 during 2018 and paid dividends of $21000 on common stock. It also has 10000 shares of 6%, $100 par value cumulative preferred stock outstanding. Common stockholders' equity was $1240000 on January 1, 2018, and $1560000 on December 31, 2018. The company's return on common stockholders' equity for 2018 is: