most common rape location is in the home of the victim or rapist. In the U.S., acquaintance rape frequently takes the form of date rape or gang rape. A 1987 survey of 7,000 students at 25 schools found that one in four had been a victim of rape or attempted rape, and 84% of those knew their attacker. The same study found that 16% of male students who admitted rape, and 10% who admitted attempting it, said they had not been acting alone. In 1985 the Association of American Colleges published a report describing what were then called "trains", in which multiple male students rape a woman who is incapacitated by drugs or alcohol. In a survey of 24 documented cases of alleged college gang rapes reported in the 1980s, 13 were perpetrated by fraternity members, nine by groups of athletes, and two by men unaffiliated with a formal group. In a U.S. National Women's Study, 20% of rapists were described as friends, 16% as husbands, 14% as boyfriends, and 9% non-relatives such as handymen, coworkers and neighbours. A 1992 study of reported rapes in inner-city and suburban Johannesburg, South Africa found 80% of rapes of adult women were perpetrated by strangers, often by men who abducted them at gunpoint on their way to work or broke into their houses. However, the majority of rapes of girls under 16 years of age were perpetrated by people known to them, usually family or friends, and sometimes gang members. In India, anti-rape campaigns tend to focus on "custodial rape": that is, rape of a woman by a man in a custodial position with higher status than hers, such as a landlord, policeman, or employer. A 2005 study by the World Health Institute found that in Ethiopia almost all sexual violence is perpetrated by the husband or boyfriend of the victim. Types Acquaintance rape is a broad category that includes all rapes except those perpetrated by people previously unknown to the rape victim. Acquaintance rape by definition includes all date rape and marital and other intra-family rape, as well as rape perpetrated by people such as classmates, co-workers, friends, neighbours, and people in business, employment or caretaker relationships. Prison rape, gang rape, child rape and statutory rape are often also forms of acquaintance rape. War rape and corrective rape fall under the category of acquaintance rape if the parties have met before the