I play in a competitive co-ed league in Korea. I looked at our scoring and every team averaged between 9 and 11.5 runs per game. Of course, it is a co-ed league, which helps to keep the scoring down, but I have played in some high-scoring leagues before, too.
In 2010, I was a silver medalist in the World Firefighter Games. We lost the Gold Medal Game to Team Venezuela by a score of 24-13 (I think). The strange thing about that game is that EVERY run they scored came via long ball, sometimes with runners on, but a lot of solo shots.