Geographic Unit: Five-digit Zip (June 1998 Primary Election) Geographic Coverage: State of California by Zip Data and Election: Registration Tape (June 1998 Primary Election) This report is a list of five digit zips and the percent of each zip in different congressional districts. It is derived by processing the registered voter tape for the entire state and creating a cross-reference table of zip code and congressional district (each individual voter record has this information on it).