40 ILCS 5/5-120: Interest.

"Interest": (a) Interest at 4% per annum for any policeman who was a participant or a contributor to this fund on December 31, 1953; and (b) interest at 3% per annum for any future entrant not a participant or contributor to this fund on December 31, 1953, who becomes a participant or contributor after December 31, 1953.

For fund accounts, credits, transfers and charges, "interest" means interest at 4% per annum as to amounts applicable to any policeman who was a participant or a contributor on December 31, 1953, and interest at 3% per annum as to amounts applicable to any future entrant who was not a participant or a contributor on December 31, 1953, but who becomes a participant or contributor after December 31, 1953.