There are European countries with 5%, 10%, 15% unemployment numbers. It'd be insane if they had that percentage of completely recluse population. And they obviously don't.
He said 1:1 correlated, not 1:1 equal. I.e. if for the sake of argument one in five unemployed are shut-ins but nearly no employed people are, then you have a good starting point to estimate populations.
Unemployment of the youth in Spain is at >33% now.