| Year/Season | M | s.e | 95% confidence interval | F | p | |
|---|---|---|---|---|---|---|
| Lower bound | Upper bound | |||||
| 2012 | 23.25 | 5.66 | 9.38 | 37.12 | 7.411 | 0.000 |
| 2013 | 23.5 | 0.87 | 21.37 | 25.63 | ||
| 2014 | 19.0 | 0.41 | 18.0 | 20.0 | ||
| 2015 | 24.5 | 3.66 | 15.53 | 33.47 | ||
| 2016 | 40.0 | 6.06 | 25.15 | 54.85 | ||
| 2017 | 36.25 | 4.87 | 24.32 | 48.18 | ||
| 2018 | 53.5 | 6.12 | 38.51 | 68.50 | ||
| Spring | 32.86 | 3.143 | 25.17 | 40.55 | 0.453 | 0.718 |
| Summer | 28.86 | 5.0 | 17.61 | 40.1 | ||
| Autumn | 28 | 3.735 | 18.86 | 37.14 | ||
| Winter | 36 | 8.753 | 14.58 | 57.42 | ||