| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.7 | 3.91 | 1.77 |
| 2024 | 1.54 | 2.48 | 1.19 |
| 2023 | 1.9 | 2.39 | 1.65 |
| 2022 | 1.85 | 2.49 | 1.47 |
| 2021 | 2.32 | 2.69 | 1.99 |
| 2020 | 3.82 | 5.58 | 2.43 |
| 2019 | 2.58 | 3.67 | 2.09 |
| 2018 | 2.87 | 3.58 | 2.11 |
| 2017 | 3.67 | 4.28 | 2.82 |
| 2016 | 4.53 | 5.19 | 3.7 |
| 2015 | 6.62 | 10.83 | 3.79 |
| 2014 | 6.36 | 9.98 | 3.16 |
| 2013 | 5.61 | 7.26 | 3.78 |
| 2012 | 4.78 | 5.51 | 3.3 |
| 2011 | 6.15 | 9.01 | 4.79 |
| 2010 | 8.5 | 10.41 | 7.17 |
| 2009 | 6.03 | 8.52 | 4.17 |
| 2008 | 5.24 | 10.13 | 2.45 |
| 2007 | 6.43 | 8.33 | 4.74 |