Complex sentence: The Land Registry House Price Index (calculated on behalf of HM Land Registry by Calnea Analytics) uses Land Registry's own data, which consists of the transaction records of all residential property sales in England and Wales.
Split into simpler sentences: The Land Registry House Price Index is calculated on behalf of HM Land Registry by Calnea Analytics. It uses the Land Registry's own data, which consists of the transaction records of all residential property sales in England and Wales.