3,000 males and females aged 16 years or over, who were selected randomly nationwide, were targeted in the stratified 2-stage random sampling method. Out of these, the number of persons actually surveyed came to 2,211, of which 1,073 were men (48.5%) and 1,138 were women (51.5%); the response rate was 73.7%.

  Individual interviews were performed based on a questionnaire issued mainly under the initiative of the United Nations Interregional Crime and Justice Research Institute.