Where Are All the Female Plumbers?

We've been having a lot of plumbing problems at our house the last couple of months and so plumbers have become regular visitors. It occurred to me that I have never, in my life, seen a female plumber. So, of course, I had to investigate this further:

According to a Bureau of Labor Statistics report, using Current Population Survey data, in 2004 only 0.9% of the people employed as "pipelayers, plumbers, pipefitters, and steamfitters" in the U.S. were women.

This was not, however, the most male-dominated occupation. Women are only 0.1% of all "dredge, excavating, and loading machine operators" and 0.2% of all "cement masons, concrete finishers, and stonemasons."

On the flip side, women constitute 98.8% of all "dental hygienists" and 98.1% of all "preschool and kindergarten teachers."

And now the investigation gets even more interesting. Here are the median weekly earnings for employees of both sexes in those industries:

plumbers -- $690
cement masons -- $556
pre-K and K teachers -- $521
dental assistants -- $474 (for some reason, hygienists were not listed as a separate category)

Hmmmm ....