A company has 3 million shares outstanding that are currently priced at $4 each and have a beta of 1.3. Seven years ago the company issued bonds with a total face value of $3 million. One bond has a face value of $500,000. The bonds have a coupon rate of 3% p.a. and coupons are paid every six months. The bonds mature in eight years from today. The bonds currently yield 2% p.a., the return on the stock market is 7% p.a., the risk-free return is 1% p.a., and the company tax rate is 30%. What proportion of the firm's capital structure is debt?