Depends on the bike, my route and the way I was riding.

On my cyclecross in OR, I used to get buzzed 1-2 times a month with lulls on occasion. I was run off the road twice (both from right turners forcing me into the left meridian, different locations) and hit once. This is over a period of 5 years.

On my recumbents in the Puget Sound (WA) it was less often but there were incidents maybe 4 times per year. I did have one idiot mad that I was in the lane and try to bump brush me into the side of the road (I was going over the speed limit), I wish I had set up a video camera for that.

I have greater situational awareness now and work hard to prevent situations that could cause incidents. I am not shy about ringing my little bell, hitting my horn or yelling to prevent a threat.