What is going on with caravan numbers.

The reports on caravan sales & trends say there is a big upswing in sales & ownership. Production & demand are sky-rocketing they say.
But where are they?
Caravan parks are disappearing at a million miles per hour & the remaining ones are complaining about falling patronage here in Qld.
In the last 25 years 24 caravan parks in the area of Cairns from Gordonvale to Palm Cove have gone. There is only 1, or maybe 2 at the most new ones built in that time.
If this was just a trend of caravanners avoiding Cairns it should show up by putting greater preasure on other Qld coastal caravan parks. But it doesn't.
If it was a matter of caravanners avoiding Qld it should show in increased demand on caravan parks in NSW & NT.
The free roadside stops can't be absorbing the increase in numbers. Free roadside stops have been well patronised since I was a kid. They are reducing in numbers as well.

So where are the caravans?

If they are out there as they say, what are they doing?
Do they sit at home more often?
Do they take journeys of shorter duration?

Does anyone actually know the growth figures in caravans in Australia?