| 年份 | 均值 |
| 2013 | 20.75 |
| 2014 | 19.50 |
| 2015 | 22.00 |
| 2016 | 22.00 |
| 2017 | 22.00 |
| 2018 | 22.83 |
| 2019 | 20.33 |
| 2020 | 22.63 |
| 2021 | 22.83 |
| 2022 | 22.83 |