A method and system for generating a real estate property index are disclosed. Real estate data including price data, property data and time of sale data are entered into computing apparatus (60). The time of sale data is manipulated to provide consecutive triple times giving two consecutive time periods (March, April, May 2007 and April, May, June 2007). A transform function, preferably a log function, is generated with two time dummy variables and the coefficients of the two time during variables extracted and added to generate a transformed growth rate. The reverse transform function, preferably an anti-log function, is generated to provide the desired untransformed growth rate.