This graph shows the same results as the previous page, but with the pre-baiting results excluded. The smaller vertical axis is now able to show variations more sensitively. Note the huge surge in numbers during 2014. By April and July 2015 this had been brought under control in the majority of the Ark, with the persisting positive tunnels largely from one area in the south. Further improvement has followed with conversion of all 100m spacing areas in the south Ark to 50m spacing.
(Click on image to see an enlarged view)