Any idea how many online players use PT and such?

[JussiUt]

I know there's no way to get solid information about this but it'd be interesting to know exactly how many users of PT are against me in an average table. How common is it anyway to use specific poker software among online players? The higher the stakes the better the players so probably there are more PT users in high stakes games.

I'd like to just hear your estimation. What's your gut feeling?