Surveys of victims of crime have been undertaken in many cities and countries, using a common methodology to aid comparability, and have generally included questions on sexual violence. The United Nations has conducted extensive surveys to determine the level of sexual violence in different societies. According to these studies, the percentage of women reporting having been a victim of sexual assault ranges from less than 2% in places such as La Paz, Bolivia (1.4%), Gaborone, Botswana (0.8%), Beijing, China (1.6%), and Manila, Philippines (0.3%), to 5% or more in Istanbul, Turkey (6.0%), Buenos Aires, Argentina (5.8%), Rio de Janeiro, Brazil (8.0%), and Bogota, Colombia (5.0%).