Do immigrants from some countries commit more sex crimes?

In Bristol last November three men and a 17-year-old boy, all Afghans, gang-raped a 17-year-old girl over several hours. Beforehand they had groomed her on Snapchat and plied her with alcohol; afterwards they fled to France in a lorry. The French authorities returned them to Britain, where they were convicted and, on October 6th, sentenced to long jail terms. In court the girl described how "listening to it all again from the lawyers kept me reliving everything that happened to me".