Centre shift and averaged P₃ parameters. Clearly seen are the five most disturbed clusters in the upper right corner with the largest w and P₃ values. The intermediate cases are bounded by the two vertical dashed lines below the horizontal line, and the regular clusters are located in the left lower corner. Clusters 3, 6, 7, and 10 have very low P₃ values, however, they are classified as disturbed given the large centre shifts. In the same way 20, 24, 26, and 31 are disturbed due to their large P₃ values. Clusters are numerically labelled by their w values in descending order.