Year | Mean | Mann-Whitney U | Wilcoxon | Z-Statistics | Asymptotic Significant (2 Tailed) | Sen’s Estimator | Number of Samples |
1971-1980 1981-1990 | 11.3 9.7 |
42 |
97 |
−0.605 |
−0.545 |
0.146 | 10 10 |
1991-2000 2001-2010 | 11.6 9.4 |
39 |
94 |
−0.832 |
−0.406 |
−0.535 | 10 10 |