I looked at this today and found it rather interesting.
The RV Industry Association's December survey of manufacturers found that total RV shipments ended the month with 27,516 wholesale shipments, a decrease of (-3.0%) from the 28,363 units shipped last December.
Towable RVs, led by conventional travel trailers, totaled 24,649 units for the month, a decrease of (-2.2%) compared to last December’s total of 25,207 units. Motorhomes finished the month with 2,887 units, down (-9.2%) compared to the December 2018 total of 3,156 units.
RV shipments have reached 406,070 units for 2019, down (-16.0%) from the 483,672 units last year.
Park Model RVs finished the month up 18.5% compared to last December with 243 wholesale shipments. Park Model RV shipments ended 2019 up 16.1% from 2018 with 4,213 shipments for the year.
More information is available on the RVIA site.