Blueberry Corporation has 450,000 preference shares trading at $4 each. Ten years ago, the company issued bonds with a total face value of $7 million. One bond has a face value of $100,000. The bonds have a coupon rate of 3.5% p.a. and coupons are paid annually. The bonds mature in ten years from today. The bonds currently yield 2% per annum. The company has 2 million ordinary shares outstanding that are currently priced at $20 each and have a beta of 0.80. The return on the stock market is 6% p.a., the government bond rate is 1.5% p.a., and the company tax rate is 30%.

What proportion of the firm's capital structure is ordinary equity?