The numbers don't add up to 100%. I don't understand the tie to education level for one group and not using it for the others, too. It also doesn't distinguish between those who left the workforce voluntarily and those who didn't.
It is interesting that 41% leave the work force in their 50's. That's pretty high when the media rhetoric suggests that more older Americans will continue to work past retirement age.
In this age of information overload, the truth has to be out there somewhere!