How do I calculate the ratio of debt to assets?

Kellogg company is the world's leading producer of ready-to-eat cereal products. In recent years, the company has taken numerous steps aimed at improving its )rofitability and earnings per share. Presented below are some basic facts for Kellogg. 2014 2013 Net sales $14,580 $14,792 Net income 632 1,807 Total assets 15,153 15,474 Total liabilities 12,302 11,867 Common stock, $0.25 par value 105 105 Capital in excess of par value 678 626 Retained earnings 6,689 6,749 Treasury stock, at cost 3,470 2,999 Number of shares outstanding (in millions) 358 363