| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.21 | 1.61 | 0.94 |
| 2024 | 1.4 | 2.76 | 0.75 |
| 2023 | 2.43 | 2.8 | 1.94 |
| 2022 | 2.2 | 3.91 | 1.65 |
| 2021 | 1.66 | 2.18 | 1.41 |
| 2020 | 2.08 | 2.72 | 1.56 |
| 2019 | 1.66 | 2.26 | 1.23 |
| 2018 | 1.67 | 2.42 | 1.2 |
| 2017 | 2.57 | 3.32 | 2.14 |
| 2016 | 6.48 | 8.89 | 3.12 |
| 2015 | 8.87 | 21.49 | 3.6 |
| 2014 | 4.57 | 9.21 | 2.91 |
| 2013 | 3.94 | 5.66 | 2.56 |
| 2012 | 3.7 | 4.84 | 2.97 |
| 2011 | 5.84 | 7.79 | 4.28 |
| 2010 | 6.03 | 8.37 | 4.16 |
| 2009 | 5.73 | 7.74 | 3.64 |
| 2008 | 3.94 | 5.09 | 2.7 |