Ann: Appendix 3B, page-6

They invest $1000, 500 options bonus.

After 4 years they've gotten $360 from the 9% coupon then the $1000 back from their bond.

At today's SP, the 500 bonus options can be converted at a cost of $648 ($1.296056 each) and sold immediately at $1.91 for $955, so a profit of $307.

After 4 years, they've gotten $667 profit on their $1000 investment. 9% coupon per annum, but 16.7% PA when accounting for the current value of the options.