R.C had earnings per share of $8 in year 2010, and it paid $4 dividend. Book value per share at year's end was $80. During the same period, the total retained earnings increased by $24 million. R.C has no preferred stock, and no new common stock was issued during the year. if R.C's year-end debt (which equals its total liabilities) was $240 million, what was the company's year-end debt ratio?