Net of Fees Return

If I have gross monthly returns of: January=1.8% February=2.1% March=1.3% April=-1.5% May=2.6% June=2.35% July=-0.65% August=3.2% September=1.4% October=1.6% November=-1.5% December=2.4% How can I adjust these returns to account for a 20% annual incentive fee of profits? Is there a particular formula used to adjust monthly returns net of an annual fee?

Annual return = [(1+Jan return) * (1+Feb return) * … * (1+Dec return)] - 1.

Fee = 20% of annual return.

Sounds good?

I’m looking to adjust the monthly returns, not calculate the overall return. I can’t just multiply the monthly return x 0.8 because that won’t adjust for compounding. I need to know what the monthly returns are net of the annual profit sharing fee.