bikes value for tax appraisel

[Banned_imp]

In NC we have property tax on our vehicles , including motor cycles.
Last year my 2013 CB 1100 with ABS was appraised at $ 9,900 and my 2014 DLX at $ 7,652
I just got the bill for my 2018 tax and my 2013 and it is still $ 9,900 !
Is it that very few 2013 with ABS were sold , perhaps I should sell my bike to Buncombe County / NC tax office !

How is your fee calculated, is it a %? So theoretically each year your bill should be less as the vehicle depreciates?

Here vehicles are rated by weight, the heavier the vehicle the more you pay. My Tacoma is $143, motorcycles are $43.