Every five years, the Department of Land Valuation determines the value of every property in Bermuda. That valuation is a snapshot of the rental market. Currently, valuation lists in Bermuda reflect the value as of 1 July, 2014. The next valuation will take place in 2020.
A property can be privately rented for whatever the market place is willing to pay, unless it is under the rent control threshold. See more information on rent increases. 
If you disagree with the appraised value of your property, you can object to the annual rental value.