I can't believe I'm doing actual research on Fortuna Dusseldorf's stadium costs but I am

Apparently the stadium was a tremendous mistake to build in the first place and it's losing tons of money. However, regarding the football club as one of the entities renting the place, it's not quite as grim. I couldn't find a concrete number that the club has to pay in rent, but what I did find is the number that the stadium owner was calculating for the rent over an entire year: 6.6 million Euro. Now, the
Westdeutsche Zeitung (sorry, German only) claims that this estimate is ludicrous because there aren't enough rock bands playing. They also say the city pays 1.79 mio of that.
So what does this impressive research tell us (besides Dale having too much time)? Well I might be wrong and maybe it's more complex than this, but it looks to me like whatever the club is paying for rent can't be more than a couple of million a year.
I hope I'm getting this right or this was a tremendous waste of time