| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 5 | 5.8 | 4.22 |
| 2024 | 4.4 | 5.47 | 3.51 |
| 2023 | 5.89 | 8.1 | 4.47 |
| 2022 | 5.39 | 7.1 | 3.56 |
| 2021 | 5.73 | 7.64 | 4.85 |
| 2020 | 7.02 | 9.26 | 5.46 |
| 2019 | 6.14 | 8.13 | 3.77 |
| 2018 | 4.76 | 7.22 | 3.28 |
| 2017 | 6.5 | 8.55 | 5.2 |
| 2016 | 8.93 | 12.13 | 7.6 |
| 2015 | 16.04 | 30.91 | 8.3 |
| 2014 | 10.46 | 12.46 | 8.44 |
| 2013 | 9.51 | 11.9 | 7.93 |
| 2012 | 8.91 | 10.12 | 7.45 |
| 2011 | 12.87 | 20.18 | 9.17 |
| 2010 | 18.45 | 23.09 | 13.8 |
| 2009 | 12.25 | 18.93 | 6.67 |
| 2008 | 10 | 19.12 | 4.26 |
| 2007 | 16.51 | 21.12 | 13.49 |