Thomas,
I believe there were about 50 chapters people
about about 100 devs.
I'm not sure why the mean travel distance would be lower if you
include everyone - there were people from all around the world there,
many having travelled further than the average board member.
Actually, I'd be happy if you were right (and you probably are!) - it
shows, that lots of people had the motivation to come to this
"excursion".
Every single chapter was represented by at least one person - I was
extremely impressed by that.