9. AMG GW&K Municipal Enhanced Yield Fund (GWMEX) 6.35%
At just $324.4 million in assets, the AMG GW&K Municipal Enhanced Yield Fund is the smallest by invested assets in the top ten, but it offered investors an attractive 6.35% return over the past decade. The fund, which carries a 0.64% expense ratio, had five-year returns of 5.38%, a one-year return of 4.36%, and returned 3.33% year-to-date.