Sales revenues for 2015 were $800,000, gross profit was $320,000, and net income was $36,000. The income tax rate was 40 percent. One year ago, accounts receivable (net) were $76,000, inventory was $110,000, total assets were $460,000, and stockholders' equity was $260,000. The bonds payable were outstanding all year and the 2015 interest expense was $12,000. What was the firm's return on sales for 2015?