GitLab

fix summary-athletes: now gets two arguments

set register dates of the nations to 1900
using `:%s/2000/1900/g` in vim on these files

as now it is clear how the program should behave see:
https://ilias.studium.kit.edu/goto.php?target=frm_741567_102648&client_id=produktiv

This reverts merge request !39