I do wonder if there is a specific ‘ex-yugoslavia’ country that rises above the rest.
There may be no standout group from the lands of the former Yugoslavia as they are all infused with various groups of Muslims (Thanks to the Ottoman Empire) and and Christians (Thanks to the Byzantine Empire). Bosniaks, Serbs, Croations, Albanians, Macedonians... …But ex-Yugoslavia may be a politically correct way to collect a lot of people culturally/behaviorally similar to the others listed in the stats.