The biennial surveys of village population have been carried out by Kemper during August of even-numbered, non-census years since 1974.The purpose of the surveys is to update the prior ethnographic census, especially with respect to births, marriages, deaths, and migrations of persons into and out of Tzintzuntzan.Also, the biennial survey allows the construction of new houses to be documented on updated maps of the community every two years. These survey data are combined with data from the parish (and municipal) archives to prepare for conducting upcoming decennial ethnographic censuses.The system for doing the surveys has evolved over the years so that presently a computer file (based on the last decennial census) lists each household (and all of the individuals therein) in sequence by blocks. Then, the appropriate part of the file is printed out and provided to the local residents who assist Kemper with the survey.These local residents serve as key informants for specific sections of the community with which they are familiar. The surveys for 1992, 1994, 1996, and 1998 have been placed into computer files. Also, the surveys include the žextendedÓ communities known officially as Colonia Lazaro Cardenas (established 1978) and Colonia Tzintzuntzita (established 1991), both located about 2 kms, south of Tzintzuntzan on the way to Patzcuaro.