The baseline reward estimate is about 6% annually. This baseline reward amount for stakers will decrease when more of the CELO supply is staked, and decrease when less of the supply is staked. If the validator group you vote for has perfect performance, you can expect to earn 100% of your rewards. If members of your validator group experience downtime, you will earn fewer rewards. This amount will decrease rapidly the longer that validator members are offline. Delegators are directly compensated by the protocol. Validators do not have a comission. This also means that delegators do no have tokens taken away from them when validators are slashed.