Ten years ago ABC made a $10 million investment in DEF and received 2.5 million class A convertible preference shares, each of which can be converted into two DEF ordinary shares. Four years ago ABC provided a second round of financing when it received 2 million class B convertible shares in exchange for $10 million. Each share of the class B stock can be converted into three DEF ordinary shares. DEF just announced an IPO and will convert all its outstanding stock into ordinary shares. After the conversion DEF will have 55 million shares outstanding and will create another 5 million shares for sale in the IPO. After the IPO the shares will trade at $55. What is the annual return on ABC's first investment into DEF?