When I was at GM. Marketing had an independent company do a survey of all off-road type vehicles. Along with that survey, the took info from other manufacturers to see the percentage of their vehicles that were actually off-roaded. One thing they did conclude was the meaning of off-roading a vehicle was different from one person to another. Some considered off-roading the vehicle going to a desolate area to camp, some considered mudding off-road and some considered rock crawling as off-roading.
What they found out was only 15 percent of off-road classified vehicles go off-road.
For Jeeps it was in the 60 percent range with Rubicons leading the pack. (And for rock crawling and living in Moab and visiting Ouray a few times, it can easily be said the the greater majority of vehicles are Jeeps.)
Land Rovers were about 7 percent.
With Hummers H2/H3 it was about 5 percent (but that was back in 2008, probably a bit higher now...maybe, and not sure why H1s were never considered in the surveys)
These stats come close to other stats done by other firms. MSN did one a few years ago along with others.
And I think anyone who has been in Ouray or Moab a few times will confirm that Jeeps are the number one vehicle for off-roading in those areas. Not necessarily because they are any better, but because there are so many used ones available, and parts....damn they almost sell parts on the corners, and you can always find a few laying around on the trails.
The big thing now for off-roading is not street vehicles. Just talk to those who have lived in Ouray or Moab for many years, and the off-road usage is being overtaken by ATVs/UTVs. Consider that years ago, engineer pass in CO used to have a few ATVs running the trail; whereas now, by early AM on a nice day, the parking area at Engineer is full of pickup trucks and toy hauler trailers and the trail is full of ATVs. (This comes from someone who has monitored those trails now for 15 years in July.) During weekends, Kane Creek in Moab, during the warmer months is loaded with ATVs/UTVs to the point that they block Hurrah Pass at times.