[gtc]

I think you're right. The list is of the 100 most commonly insured cars at Hagerty, so 60's American iron probably dominates the list
As an example, there were over half a million mustangs built in 1965 alone - more than the entire run of air cooled 911s, I'd guess.
I doubt many Porsches made the list, let alone the ones that have really skyrocketed in value.