Buckman has made some valid points,
A similar but more severe story played out in the 1990's . In late 1980's the UK touring caravan market was about 40K units but , by 2000 it dropped to about 20K and there were several consequences. Many of the smaller caravan manufacturers were swallowed up by bigger competition, It affected OEM suppliers also, and several of the big names changed their UK strategies. I know, as I was made redundant from one of them as it was closed down after being bought out by a competitor.
Historically the UK caravan market has usually been slower to react to national financial issues, but it seems it might be catching up and it certainly can be affected by new trends, like smaller cars not being able to tow such large caravans, Changes to the driving licence restricting what people can drive and tow, fuel costs. Site costs, etc.