Why are girls' track records falling faster than the boys?

I was trolling around the PIAA's website looking for the state pole vault record for a question I was posting on GameTimePA's Facebook page. What I found was a list of all boys' and girls' PIAA records, plus the national marks, too.

Unfortunately, the state records haven't been fully updated, but what caught my eye was the number of national records that are still standing from the 1980s and 90s on the boys' side.

It struck me as a bit odd, so I totaled the records by decade for each gender. Here's what we have:

National recordsGirls        Boys2000s -- 15   2000s -- 71990s -- 2   1990s -- 51980s -- 0   1980s -- 51970s -- 1   1970s -- 1

Seven of the 15 girls' records were set in the past four years. Why are the girls' obliterating records now? Anyone want to offer up a theory?

Bonus trivia:Name the two records (one boys, one girls) that were set in the 70s and have yet to be touched.

(Click on read more for the answers.)GIRLS: 1976: long jump (22-1 3/4) set by Kathy McMillan (Tennessee)

BOYS: 1979: Shot put (77-0) set by Michael Carter (Texas)