Clan Points

I read the Clan FAQ saying that "For every 500 EXP earned by a clan member one (1) clan point is awarded to that player’s clan."

In fact, after I join a clan, I don't get 1 point for each 500EXP, I get a point for around each 1000-2000EXP.

Can someone tell me why?
Did I do everything wrong?

kate