Year | Mean | Mann-Whitney U | Wilcoxon | Z-Statistics | Asymptotic Significant (2 Tailed) | Sen’s Estimator | Number of Samples |
1971-1980 1981-1990 | 8.7 12.3 |
32 |
87 |
−1.361 |
0.174 |
1.841 | 10 10 |
1991-2000 2001-2010 | 11.3 9.7 |
42 |
97 |
−0.605 |
0.545 |
−0.211 | 10 10 |