[Gogar]

I think that the retailer they quoted was really just commenting on the fashion trends and "Push up Bras", which typically add two cup sizes.

So, when she's saying the average bra used to be a 34B and is now a 36D, the figure is skewed due to the popularity of push-up bras and she's really just saying that women are a little bit bigger around than before and their cup sizes are the same.