Catalan Zodiac Rose S.XV

[Mauro]

I see. It is strange that the numbers are written from right to left instead of from left to right. I mean, for example, IIIX for XIII, or IIIVXX for XXVIII.

They are written normally if you look at them from the other side (what seems to be an 'a' at first glance is a 'v', looking from the other side).