Over 50 percent of the families in communities of 100,000 did not own cars, the average family income was less than $6,000 per year, and the average educational level was 7.2 years compared to 12.2 years in the City of Los Angeles. Many thousands of undocumented Mexicans and their families resided in the Los Angeles area and were often not bilingual. In 1977, 13 major gangs represented over 3,000 members. Each gang was turf-oriented and dominated a territory usually bordered by a freeway, public park, or other natural barrier. Gang members did not target police officers, businesses, teachers, or adults, but all community residents were directly or indirectly affected by gang presence. In 1975, over 23 percent of all violent crimes in Latin communities involved gangs. Due to concerted police efforts, this figure was reduced in 1976. Realtors and businesses also initiated programs to productively involve gang members and reduce gang violence, and the need for patrol officers in public housing projects was recognized. Community involvement and improved police-gang communication served to reduce gang violence.