Set over Set

What are the odds?...

I have been playing on UB for over a year, and I have never seen a situation like this:

Over the course of 18 hands on a $3/$6 table (10 seated), there were 20 total pocket pairs dealt that were shown down (so, not including any that were folded during the course of the hands). Isn't that excessive?

Also, I would like to know the following if anyone knows:
1) What are the odds of exactly 2 players (out of 10) being dealt pocket pairs on a given hand?
and
2) What are the odds of those SAME 2 players then hitting sets on the flop?

I know someone out there will know the answers...