I bought my house 24 years ago. It was bought new. How do they value it? The current 'rebuild' cost in my insurance is more than I paid for the house originally.
I'd be happy with 0.48% of the purchase price, not sure the council would be as happy to give me such a reduction though!
If it goes on current valuation, who's paying for it to be valued? Certainly not me and I doubt the local council want to fork out for each house to get a current valuation.