I'd be interested to see what the numbers would look like if we could get nearly all VFTTers to take it - I was suprised the numbers seem so high myself Chip, but now I'm curious about the percentages for the larger group and non-VFTTers as well.
Keep in mind that all someone has to do is hike solo once in a while in the winter to be part of the 85%. Many of those 85% could still hike in groups very often as well.
As far as not running into solo hikers more often, If I am hiking solo and want solitide, I tend to avoid popular trails at popular times. In winter, that is not so easy, but in summer, I avoid the popular trails and I sometimes start very early or very late any time of year. I plan trips with crowd-avoidance in mind. It's not cuncommon for me to hike all day and only see 1-2 others or no one for that matter. I hiked Garfield 3 weeks ago on a Saturday without seeing a single other person on trail and no prints showing anyone had been on trail or across the ridge. Those days in winter are rarer than they were 10 years ago, but there is something very special about being the only one on the mountain.