Hello :-)
Are you going on the China trip as well,if you dont mind me asking?
To answer your queston with honesty I find the marjority of people over the 60 mark.I went to Belgium and Italy where a more mixed group,ie 40s and 50s but still the majority a older group.
Spain,well I was the youngest,and so was another girl at 36,the rest plus 67! I found been younger on that trip made the people not talk to me as much.Felt abit left out,having said that my favorite was an 80 year old lady,we spent alot of time togther.
Without going on I found on my trips no one as young as me,but they were great and I enjoyed the company on most the trips.The favourite group I went with was to Russia last year,apart from me,the youngest was 58,but the best group Id travelled with.
Id like more 30s and 40s though.
Also always more women then men.
Hope this helps!