LOL. This is a tough fucking question I don't know a thing about Germany (but I'll do some research).
Amount of Americans who speak English as dominant language = 95%
Amount of Americans who can speak German is 1.38M = .05%
Amount of Germans who speak German as dominant language = 95%
Amount of Germans who can also speak English = 70%
Most Germans are taught English as their first foreign language.... and seem to actually learn it fluently.
Most Americans try to learn Spanish then give up right after college.
I think we need more data here.
Like who is your target audience? Is it Germany? Is it Germany & Europe? Europe & America or the whole world?
Personally, I wouldn't make more than 20% of the links in English. I say that because I'm American and most American's do not follow or care about Germany.
But I assume that a fair deal of English speaking Europeans follow German sites. Like I would assume a good deal of French, British, etc do.
But thats like saying a lot of Americans visit Canadian sites cause Canadas our neighbor.... but we don't. We don't care. So maybe the French, British, etc
don't either. Maybe noone really cares about German sites except Germans and maybe you should keep most the links in the native tongue of the
country you're targeting.... just to be safe.
ps. Very obvious but as the site grows and you get some organic traffic, just use that data to correct your ratios.