Using German date format in Numbers

Since the last update of numbers to version 3.6.1, the program doesn't recognise the German way to write a date anymore. (dd.mm.yyyy)

It only recognises the American or British way with slashes (dd/mm/yyyy) which really suchs, because all my sheets and cvs.files I get from my bank for example are using the German format. Numbers now thinks this is just a number and not a date, so I can't even sort the table anymore. When I try to do it, it will do (15.01.2015 --> 15.02.2015 --> 16.01.2015 --> 16.02.2015) and so on.

Does anyone know how I can get Numbers to recognise the dd.mm.yyyy-format as a date again?

Help is appreciated.