A range of studies have concluded that at least 10% of physical and sexual abuse victims forget the abuse. The rate of delayed recall of many forms of traumatic experiences (including natural disasters, kidnapping, torture and more) averages among studies at approximately 15%, with the highest rates resulting from child sexual abuse, military combat, and witnessing a family member murdered. The rate of recall of previously forgotten traumatic events was shown by Elliot and Briere (1996) to be unaffected by whether or not the victim had a history of being in psychotherapy. Linda Meyer Williams, who interviewed 129 adult women who were treated for verified sexual abuse at a hospital as children between the ages of 12 months to 10 years, found that among women with confirmed histories of sexual abuse, approximately 38% did not recall the reported incident on file at the hospital 17 years later, especially when it was perpetrated by someone familiar to them. This study is routinely cited as evidence of repression, however 88% of women interviewed said they had been molested, despite not reporting the specific incident on file-- a figure which suggests the opposite of the repression theory. Hopper cites several studies of corroborated abuse in which some abuse victims will have intervals of complete or partial amnesia for their abuse.