here for a more detail. In this case it is 0.34 or just over third.
Now each Ward has a new value that can be measured above or below the line by using the equation to determine the score if it were on the line and subtracting that score from it actual score. This new score can be mapped to show those Wards that have a higher and lower score than predicted by the line.
We know from previous post that entertainment venues has a high influence on the occurrence of violence, including robbery, which explains some of the high scores. The Wards that do not have that "excuse" and have high scores are therefore interesting. So are the Wards with lower than predicted scores, especially those shown in green. Is it possible that good policing may be an influence here?