"Gang activity remains a widespread problem across the United States, with prevalence rates remaining significantly elevated in 2008 compared with recorded lows in the early 2000s. Approximately one-third of the jurisdictions in the National Youth Gang Survey (NYGS) study population1 reported gang problems in 2008. This is a significant change over the 2002 estimate, but a statistically negligible one from 2007. The 13-year trend is shown in figure 1. The National Gang Center estimates that 32.4 percent of all cities, suburban areas, towns, and rural counties (more than 3,330 jurisdictions served by city and county law enforcement agencies) experienced gang problems in 2008. This represents a 15-percent increase from the 2002 figure. Approximately 774,000 gang members and 27,900 gangs are estimated to have been active in the United States in 2008. The number of gangs increased by 28 percent, and the number of gang members increased by 6 percent from 2002 to 2008 (see table 1)."
National Criminal Justice Reference Center:http://www.ncjrs.gov/