Overall and single-victim school-associated student homicide rates decreased significantly during July 1992-June 2006; both decreased from 0.07 per 100,000 students to 0.03 per 100,000 students (p < 0.001 and p = 0.004 by chi-square test, respectively). However, rates for overall and single-victim school-associated homicides during a more recent period, July 1999--June 2006, did not change significantly (Figure). During both periods (July 1992-June 2006 and July 1999-June 2006), multiple-victim student homicide rates remained stable.