It's early 90's, in 1991 for instance... I know that the air traffic was several times lower than today where the common folk can take one plane or two at least

It's early 90's, in 1991 for instance... I know that the air traffic was several times lower than today where the common folk can take one plane or two at least on a yearly basis because of some job interview (or holydays), but it's still incredible. German airports are huge and they are basically the hub for Europe.