This article [1] mentions 40% of sick days being from people with long-term (> 6 weeks) illnesses. That's data from one of Germany's large insurers. While I don't know the proportion of those with long-term illnesses, if we assume it's at most 10%, then the average for people with "normal" short-term illnesses is at most 12 days. So much lower.
[1] https://www.deutschlandfunk.de/sind-die-deutschen-wirklich-h...