What is THORChain interest rate?

Excuse me, could you please elaborate on the THORChain interest rate? I understand that THORChain is a decentralized liquidity protocol designed to facilitate cross-chain swaps and swaps without intermediaries. However, I'm curious about how the interest rate for holding THORChain's native token, RUNE, is determined. Is it a fixed rate, or does it fluctuate based on market conditions? Also, are there any incentives or penalties associated with holding RUNE tokens, and how do they affect the overall interest rate? Thank you for your time.