I have no idea.
Perhaps more mothers are deciding to stay at home to raise their children.
My SIL did just that and as her children grew up she is putting more of her energy into what used to be called "charity work". If you asked her if she wanted a paying job she would look at you in disbelief and ask when she was suppose to fit one in to her schedule. And of course a large number of the under 23 crowd believe that school is their job.
I don't doubt there are people out there that are just bone lazy or that there are people who are so depressed from having work doors slammed in their face that they don't want to go through that again.
But you would have to break them out from the people who have a non-paying job before you can draw accurate conclusions.