Here's a breakdown:
* Native speakers: Nearly all of Germany's population speaks German as their native language. The exact number is hard to pin down, but it's estimated to be around 95%.
* Fluent speakers: This includes native speakers, as well as those who have learned German as a second language and are fluent. This number is likely even higher than 95%, with many immigrants and people from neighboring countries being fluent in German.
* Anyone who speaks German at all: This includes people who may only speak a little German or are learning it. This number would be almost 100%, as even people who primarily speak another language are likely to have some basic German skills in a country where it's the official language.
Therefore, it's safe to say that the vast majority of the German population speaks German. It's the official language and the most common language spoken in the country.