Since STABLES_RATIO_MULTIPLIER is 10,000, differenceInBps is calculated with a precision of 10^4.
https://github.com/code-423n4/2024-11-ethena-labs/blob/main/contracts/ustb/UStbMinting.sol#L568
It needs to calculate it with higher precision.
Sets the STABLES_RATIO_MULTIPLIER as higher value like 1e18.
