My wordpress counts the users wrongly

Hi,
my site is new and has only six users (me included), but it shows 18. Here is the screenshot: https://www.hostingpics.net/viewer.php?id=983333allmembersprob.png

How could I fix that?

I have installed buddypress and bbpress and at the beginning there were double entries but I deleted double users in the backend and now it shows 6 users there. The probleme is on the members page.

Thanks in advance for your help