68 or 69 wheel cover??

I bought a set of these wheels covers locally for my cousin's 68 dart but then I was reading in another thread on this site where someone suggested that 68 and 69 wheel covers had some kind of difference. I had always been under the impression that 68 and 9 were the same because I remember seeing these on 68 and 9 GTS long time ago but I don't remember noticing a difference.

Is this a 68 or 69 wheel cover, anyone know?