Eloethan good point. In Merseyside it probably follows the same pattern, due to the initiative being taken in assisting sex workers, but it still depends on the reporting rate. There is a consistently low take up of any women reporting that they have been raped. Anonymous questionnaires have provided stats saying that 1 in 10 women who had been raped reported it to the authorities in the 90s and there wasn't much improvement in the following decades, but this is estimated because of anonymity. This, with the failure to pursue prosecution, then a further lack of successful convictions didn't accord with the successful rate of reporting, prosecutions and convictions happening in North America, where specially trained police and lawyers were demonstrating that confidence in the judicial system was encouraging women to come forward with their complaints.
If you compare this attrition rate with the stats put out by the One Billion Rising For Justice awareness raising campaign, which claims that 1 woman in 3 suffers a rape attack in her lifetime, across the globe, it shows why initiatives like this in Merseyside are needed to help to protect women and bring their attackers to justice.