This took us a while longer to sort out. There is an interesting new category in the property price data which dates back to 1999 – it is called “other”. What it actually pertains to is commercial property or at least “non-residential” whereas all the other property transactions are for housing. There are actually very few recorded transactions in total, just 26,000, and the further back you go in time the fewer there seem to be records of. If you see here http://ukcrimestats.com/PropertySales/NationalPicture#Totals from the source data I’d say we have 2 years of quality data, of around 1,000 sales a month which makes up about 92%. From before then, the data is a bit iffy and questionably sporadic and sparse, so I wouldn’t try to to infer anything from any earlier than that – the data looks incomplete.