One in every four women will experience domestic violence in her lifetime. An estimated 1.3 million women are victims of physical assault by an intimate partner each year. 85% of domestic violence victims are women. Historically, females have been most often victimized by someone they knew. Females who are 20-24 years of age are at the greatest risk of nonfatal intimate partner violence. Most cases of domestic violence are never reported to the police. Witnessing violence between one's parents or caretakers is the strongest risk factor of transmitting violent behavior from one generation to the next. Boys who witness domestic violence are twice as likely to abuse their own partners and children when they become adults. 30% to 60% of perpetrators of intimate partner violence also abuse children in the household.