45, and in the second largest group.
It is interesting to note the relation between the age of the owners and the age of their cars. I think in Europe people mostly restore/collect the cars they saw in the streets when they were kids, while in the US people collect more the cars they started driving or that were in the streets at that time. Following that logic, most 50+ here would be US citizens, while younger ones would be of European origin. I don't know the relation in other parts of the world though. From what I've seen during my trips into Asia and Africa it seems enthousiats there are even younger.