How many blocks will Cosmos-SDK calculate validator set again and where is the code

I can only find cosmos will select top 100 validator in the first year and than grow 13% each next year from office document, but I do not know how many blocks will validator set recalculate, and where is the implement code, Can anyone tell me ? really thanks!

It’s not implemented in the code but it’s decided with governance proposal right now, for example you can look at this proposal that sets validator number to 125 and since it’s passed with the next upgrade will go live