How was this calculated?
The 'crime rate' for a given area is the number of crimes per 1000 people in that area. For each area these are calculated by dividing the actual number of crimes by the population and then multiplying by 1,000.
Force level comparisons
Crime levels are then calculated at each level using standard deviation, a way of fairly measuring and comparing the spread of crime across the force from area to area.
| More than 2 Standard Deviations above the area mean | High crime level |
|---|---|
| Between 1 and 2 Standard Deviations above the area mean | Above average crime level |
| Within 1 Standard Deviation of the area mean | Average crime level |
| Between 1 and 2 Standard Deviations below the area mean | Below average crime level |
| More than 2 Standard Deviations below the area mean | Low crime level |
National level comparisons
To work out the banding that each area is in, they are sorted and ranked according to the crime rate.
| Top 2% of areas with the highest crime rate | High crime level |
|---|---|
| Next 14% of areas | Above average crime level |
| Middle 68% of areas | Average crime level |
| Next 14% of areas | Below average crime level |
| Bottom 2% of areas with the lowest crime rate | Low crime level |
