Your retired client has accumulated investment and retirement assets totaling $9,547,000. Assume the client expects to live for another 23 years and that he assumes an annual inflation rate of 2.5 percent. To leave his heirs the future value of the $9,547,000 at the end of the 23 years, and maintain an inflation-adjusted lifestyle of $265,000 a year for all 23 years, the clients investments would have to earn an average of ______ percent a year for the entire 23 years.