http://www.sacog.org/web/text/datactr/facts/octff.htm: Facts and Figures Migration for July 1995 to June 1996 October 1996 The Department of Motor Vehicles publishes an annual report of migration based on Driver License and California ID card holders change of address. Data is presented for individuals 18 and over. The data collected is through voluntary cooperation between the states. The California DMV, based on historical data, believes that data from Colorado, Mississippi, New Mexico, and North Carolina may be under reported.