Not really too much of a difference. As you know it simply means one was made a little later in the line than the other one. For a lot of these middle year ponies I have found they tend to come in equal-ish numbers - some sets are more common with one country, some with the other but I don't think there is a definite pattern. Sure if you are looking in a local market you will find more non pat pend over here and more pat pend in the US; but thats about the most definitive thing you can say about numbers.