Ethereum’s deflationary supply / supersound.money

Could anyone point me to the right resources that highlight ETH's 2.0 supply issuances rate? Apparently there is a cap of annual issuance at 1.1 mio but where does the info come from? How does the APR/Issuance Rate evolve in relation to the available number of attestors/validators – I'm looking for the mathematical equation? Thank you!