Yes they are as they could owe billions in taxes collectively. Greek person goes to work in an office, gets his payslip Gross / Net, how can he not pay the full amount of tax?
I don't believe that you yourself believe that any businessman earning a decent amount doesn't employ a good accountant to avoid tax. That's why its important to know the % people paid.
So 344b is missing in tax revenue in Germany, the people responsible for that amount may also be the highest contributors to tax amount, that's the point.