Volatile Land Tax Valuations

How does this happen ? Down and up 20% in 2 years, how do they arrive at these figures, local sales ?

2012: Land Value 530 K
2013: Land Value 425 K (down 20%)
2014: Land Value 505 K (up 19%)
I have the same problem with my properties in Victoria. I've come to the conclusion it's what they're smoking at the time.
If you have a query contact the SVO, they will provide you with a list of comparable sales which were used to prepare your valuation. You may even be able to get these from their website if you log in.

The reason for the variablilty will be largely dependent upon the sales which occurred in the area in each of these years. The drop in price was an effect of the gfc, alot of holiday homes sold at discount prices in Byron Shire, the pick up likewise with increased activity.