Mmh...yes and no. [How does she explain this? It's true that ability users are common on the seas, even when the Devil Fruits are supposedly very rare, but that in relation to how many civilians there are, and the weak idiots who think they can overcome the cruelest waters of their world...hmph.]

The powers we gain don't come easily - the method by which we do get them is very rare where I'm from. And while I know many who do have different powers - my past crew had a few ability users - in relation to just how many civilians there are...we're a very tiny minority. Pirates usually are the ones who get the powers - or marines, because they're so useful to us both, but weakling who can't survive on the test of the Grand Line and New World aren't fit for them...and when they die, the power is reborn, for someone else to find.

Adding to that, many people who are like me hide their abilities as much as possible, so really counting how many of us exist isn't easy. And pirates are being turned in left and right - the weak ones at least - while strong pirates dispose of marine officers foolish enough to challenge them. ...So I suppose the real answer is that there is never a set amount, it always fluctuates.