How APY for a wrapped asset is calculated

Hi! I’m looking at the api docs, especially the Implied APY Get wrapped asset details | Coinbase Cloud

I want to create a historical APY and for this I wanted to know how this is calculated and where I get the information to this the calculation.

According to the white paper I need the total wrapped staked ETH and total cbETH supply

But can I get, for example,Staked ETH in settled wraps from a contract? If so, which contract?