| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2023 | 4.15 | 4.17 | 4.12 |
| 2022 | 4.21 | 4.54 | 3.87 |
| 2021 | 5.06 | 6.08 | 4.29 |
| 2020 | 5.59 | 6.16 | 5.19 |
| 2019 | 6.19 | 6.71 | 5.76 |
| 2018 | 6.49 | 8.13 | 5.49 |
| 2017 | 6.17 | 6.87 | 5.58 |
| 2016 | 5.63 | 5.88 | 5.21 |
| 2015 | 6.27 | 7.45 | 4.94 |
| 2014 | 4.76 | 6.67 | 4.4 |
| 2013 | 5.75 | 7.43 | 4.86 |
| 2012 | 6.44 | 7.3 | 5.68 |
| 2011 | 7.48 | 10.2 | 6.55 |