FHFA uses data supplied by Fannie Mae and Freddie Mac in compiling the HPI. Each of the Enterprises had previously created a weighted repeat-transactions index based on property matches within its own database. In the first quarter of 1994, Freddie Mac began publishing the Conventional Mortgage Home Price Index (CMHPI). The CMHPI was jointly developed by Fannie Mae and Freddie Mac. The CMHPI series covers the period 1970 to the present.