I think the sale of new boats is only a small portion of evaluating overall fleet strength. As has been mentioned, many factors can impact new boat sales, not the least of which is global economic uncertainty.
What is important is to see the large fleet growth in new countries like Argentina and Chile, fleet growth in the United States, a strong US worlds, the first American Continental Championship being planned, a bid to host worlds from Oman, etc.
The F18 class has fortunately grown into a truly worldwide class, it can no longer be viewed and governed like it just exists in France. I have huge amounts of respect for those who worked incredibly hard to form and develop what I am enjoying today, but now class decisions must be made in an international manner.