A private equity (PE) firm invested equity of $85 million in XYZ Corp. for a 100% ownership interest. Four years later it sold XYZ for an enterprise value of 11x EBITDA. At the time of exit EBITDA was $40 million and net debt (debt less cash on hand) was $175 million. During the PE firm's holding period it granted equity interests to management representing 10% of the outstanding shares. What was the PE firm's annual rate of return on the investment. (your answer should be in the following format xx.x%)