r = r0 + total borrowed / (total borrowed + total supply) * rX
r0- base interest rate when there are no borrowers. r0 equals to Equilibrium fee + Admin fee.
Total borrowed- total amount of EOSDT that has been borrowed from the fund so far.
Total supply- total amount of EOSDT available for borrowing (this number doesn’t change when users borrow, and only changes when lenders deposit or withdraw money).
rX- slope, which defines the terminal interest rate when all of the supply has been borrowed.
rXare available to be set and changed via Equilibrium governance.