PoS minimum rate is 5% annual.
The actual rate depends on staking activity on the network. If 100% of the coins were staking on the network, we'd get the minimum rate. The less staking activity on the network, the bigger are the rewards for those who are staking.
At the moment, staking activity is still very low on the network and the actual rate reflects it. I just minted a few FLT this morning and received about 8.3% interest on my stake for 30 days.
Actual annual rate is around 100% meaning there is only 5% of the coins actually collecting the rewards for staking. Still a lot of room to increase the activity and spreading the rewards among more participants.