How much does it cost to run a power filter 90 gph 24 hours a day for a year?

My filter use to work at 76 gph. It was on all day, and for a month, the bill increased about $3.50. It was in the winter and our habits were the same. I later decided to stop using the filter since it was kind of noisy and was really unnecessary since I frequently change the water. I shouldn't cost you too much extra. I live in Chicago.