Taxi Plates held at cost

I believe that cabcharge's taxi plates have been held on the balance sheet at cost.

Given that some of these plates are very old, the writedowns that people expect might not be there.

One needs to go over the last 10 years of financials and look at the increase in taxi plates, get a weighted average against last 10 years average price.

This is the potential impairment.

Then look at 10 years ago, how many plates what was the market price against the carrying value of the plates on the balance sheet.

If the carrying value on the balance sheet is significantly below the market price 10 years ago, then to what degree do the two offset each other?