Monero inflation is a constant amount (0.6 xmr every ~2 minutes)
So in relation to the total supply the % inflation is constantly falling closer and closer to zero (but never reaching it)
Discussion
Oh so it would have the same deflation problems as bitcoin. With non linear population growth, linear inflation is practically equivalent to no inflation
You could make that argument. I've heard some argue that it should be a small % of inflation instead of a fixed amount.
But still, a fixed amount > 0 as far as block rewards go. We'll discover how it works out in practice.