Formula to calculate commission before quota and after quota

Hey anyone who is reading this.
Here is my thing. I have a yearly quota of $140,000. I get paid commission quarterly, therefore I have a quarterly quota of $35,000. Once I get my quota, I get paid 25% on anything over my quota.

I created this table and in the "Bonus Earned" column, I have =(E17-B17)*0.25 for example. "Total GP" minus "GP quota" multiplied by 25% and that's my commission.

I'm in my second quarter and I have already passed my yearly quota, therefore, my formulas are not accurate because when I enter my 3rd quarter, the quarterly quota is irrelevant. I would like to figure out a way so it will do the math automatically.

Clear as mud?

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