Additionally there is a staking reward, for active stakers on a block by block basis. The block reward is 2% of total coins yearly, but calculated each block. Currently the block reward is roughly 5.9 DNotes per block with roughly 53 million being staked. So your reward at this rate would be more like 6+% yearly and compounding.
I am keeping track of how much my wallet stakes every (approximate) 24 hour period. What I'm finding is the APY ranges from 4.48% to 5.28%, though so far I only have four days of good data. I had two days where the APY was 4.88%. What I mean by APY is that if my wallet were to stake consistently at that exact rate for the entire year, I would get that percentage in staking rewards at the end of that year. But each day, the balance I input increases based on the previous day's staking rewards, and the APY is based on the difference between yesterday and today's wallet balance. So I don't know if it's the same formula a bank would use in calculating compound interest, but it gives me a good idea of what my wallet is doing on a day to day basis.