The rate of conviction for rape in England and Wales also varies from region to region

Postcode lottery in rape convictions 'getting worse' The Guardian, Wednesday 10 June 2009

The breakdown of some figures by police force area can be found here

It is reported that the majority of convictions for rape resulted from an admission of guilt by the defendant, whereas less than one quarter of all those charged with rape were convicted following a successful trial.

Additionally, between half and two-thirds of rape cases did not proceed beyond the investigation stage.
The majority of victims decide to withdraw their complaints, while high levels of rape complaints are essentially ignored, with reports pointing to scepticism on the part of the police and "the view that the victim lacks credibility".