Anyone have a resource with average champ gold at each level?

So i'm trying to do some calculations for AP item builds for different champs, and I've got it all set up to do quickly. Only problem I'm running into is I'm essentially just guessing what level a champ will be upon completing X gold in items, as it's not something I've really ever paid attention to in game.

I know I could estimate it myself by taking average CS, passive gold gain, kills/assists etc, and estimate XP based off CS (factoring in that I miss maybe 10% of minions I'm there for)... but was just wondering if anybody knew of a resource that had done something like this already.

Doesn't need to be exact, just a decent estimate would be very handy

Thanks