Let's suppose Police officers work 8 hours a day, work 5 days a week and take 36 days of holiday/sick a year. So that's 47 * 40 hours = 1880 hours. There are 8760 hours in a year. So, even just normal working conditions you'd expect just 1 in 5 officers available to "tackle crime" at any one time. Now factor in time in court, doing normal paperwork, training, interviewing suspects, etc, etc and consider that not all police officers work full time anyway. I don't really see 1 in 10 as much of a damning condemnation.