Year | Mean | Mann-Whitney U | Wilcoxon | Z-Statistics | Asymptotic Significant (2 Tailed) | Sen’s Estimator | Number of Samples |
1971-1980 1981-1990 | 12.9 8.1 | 26 | 81 | −1.814 | 0.070 | −0.775 | 10 10 |
1991-2000 2001-2010 | 11.4 9.6 | 41 | 96 | −0.680 | 0.496 | −0.094 | 10 10 |