What are the KyberSwap elastic fee tiers?

Could you please elaborate on the KyberSwap elastic fee tiers? I'm curious to understand how they work and what benefits they offer to users. Are there different tiers based on transaction size or frequency? How do these tiers impact the overall cost of trading on the platform? Additionally, are there any incentives for users to move up to higher tiers, and if so, what are they? I'd appreciate a clear and concise explanation of the KyberSwap elastic fee tiers system.