A standard approach would be to use a Kruskal-Wallis test to test for differences among the sectors, and then Dunns Test to see which pairs of sectors are different. This previous answer is relevant: Post-hoc tests after Kruskal-Wallis: Dunn's test or Bonferroni corrected Mann-Whitney tests?Post-hoc tests after Kruskal-Wallis: Dunn's test or Bonferroni corrected Mann-Whitney tests?