How many are left says that in 2005 there were 389 on the books. In 07 the SORN figure appears and it shows 373 licensed and 65 SORNed total 438
In the last quarter of 2016 there were 225 Licensed and 186 SORNed totalling 411 machines.
Here's the graph ...

So to my simple mind that looks like very few were imported in the first place, but that more than half of them are still on the road today, and very few of the original imports have been properly lost to the breakers or scrappers...
Do you think that's close?