Which Travel Guide for Tyrol? To Germans does not matter

My endevor to build an tourism indicator with online booksales led to a first interesting result.
In the category of worldwide travelguides, you see that the rank number (more is worse) increases comparably fast.
Whereas within the Tyrol category there are alot of books doing comparably well. The rank number increases slow.

World travel guides 

Italy travel guides

South Tyrol travel guides

Tyrol travel guides