hlango, what you are reporting does not seem to be normal to me. It sounds like your site must be very enticing in one way or another: money, sex, drugs, SEO secrets, or ??? ;-)
From the way you wrote it, nobody has managed to get inside yet? Did you put a harder limit on wrong access attempts?
Just as a matter of principle, I am allowing only three wrong attempts from the same user and also from the same host, and have a 10+ hour delay before they can try again. I also blacklist after being blocked only 3 times.
I don't have any addresses blacklisted yet, but I just raised the barrier about two weeks ago. My six sites with BWPS installed pull a total of over 200 unique visitors per day.