Prior to 4Q2014, the index was computed using stratification method. From 4Q2014 onwards, the index is computed using the stratified hedonic regression method.
Indices prior to 4Q2014 are rescaled using a factor of 100 (new index in 1Q2009) divided by 138.3 (original index in 1Q2009) multiplied on the original index level to derive the rebased index level for the respective quarters. Due to rounding, there could be some differences in the quarterly price change compared to the series before rescaling.
For more data, please refer to Housing And Development Board Resale Price Index (1Q2009 = 100), Quarterly.