@Andrea164 it sounds like a similar situation to our county.
Locally, the instruction is also that there is no Pro-Rata for how much of the year you rent out.
However, our county has instructed that we are to provide the *current* value of the items, not the purchase price. So for used furniture, cutlery, linens, etc that is much, much less. It is also easier to do. (Just look on E-Bay.)
(We acquired almost all our AirBnB furniture second hand / free from people in the neighborhood when they moved out.)
Here is an article about our sitation:
(fun trivia: I know the family in the article.)
https://www.sfchronicle.com/business/article/Airbnb-furniture-tax-generates-120-000-for-8399617.php