Wendel invests 5400 dollars in a mutual fund on January 1. On June 1, his fund balance is 3600 dollars. Wendel notices the decline, and withdraws 1100 dollars. On September 1, his fund balance is 8600 dollars, and he then invests an additional 1500 dollars. On the following January 1, his fund balance is 7100 dollars. What is Wendel's time-weighted rate of return?
Answer = percent.