I think there is a higher number of Chinese, Yugos, and Russians than there are Romanian and Albanians. If you look at the Chinese, well there is no question there, the M59/66s, just the shear number of production years, and the numbers of plain jane remaned Russians. I think while the Romanians and Albanians came in 2 small import loads, a few years apart, both sold out fairly quickly because of low import numbers in each load.
That, and 4 short years of Romanian production and low Albanian production kick the numbers even lower than the other three. There may be lower numbers in the states than we actually think, are the numbers thought to be in the US and/or numbers produced inflated or over estimated, if not I would think sales of the latter two would be a little more prevalent than they are, I just can't see why the general population would just sit on just these two nations while the more commonly desired ones change hands 10 times more frequently.