Can't really rely on number of owners unless you havea list of who they are, 2 in your case could well be garages.
I think I'm the 6th on mine if I remember correctly, previous was my dad, then the guy who we bought it from, he bought it from a garage who obviously took it as trade in from someone and thats 5 accounted for, 6 is the original owner. So in reality it's only 3 owners.