Its a fact that the data you provided does not take into account 'participation' drop off.
If you want to continue presenting statistics like that, maybe you should find a set of data that encompasses the more obvious problems?
Participation, of course, is a tricky beast. Sometimes people stop participating because they're despairing over being able to find a job, but they also retire, or get pregnant, or go back to university or (if immigrants) their home countries.
He presented no statistics at all, you presented statistics that are clearly entirely ignoring a important figure.
Neither of you seem to be at all interested in seeking the truth, each just advancing their own personal agenda.
meh.