Chan is now 30 years old and makes $500,000 a year. She expects her income to increase by 2 percent per year. She wants to accumulate 4 million by the time she reaches 60, she will make her first deposit on her 31th birthday and the last deposit on her 60th birthday. What fraction of her income (in percent) does she need to set aside? Assume her retirement funds are conservatively invested at an expected rate of return of 4 percent a year. Ignore taxes.