No one really knows as there is no international or aggregate register of these cars, so its a combination of guesswork, gut feeling, sightlngs, patchy statistics per country, local car club memberships etc.
I was led to understand that UK registrations are tracked and more than 50% of Pagodas first registered remain registered (on the road).
Many on the forum believe that maybe 50% of all Pagodas manufactured still exist, and it seems reasonable that the later the year the higher the survivor proportion