| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.61 | 4.07 | 2.22 |
| 2024 | 1.26 | 4.6 | 0.51 |
| 2023 | 0.93 | 1.01 | 0.76 |
| 2022 | 0.8 | 1.09 | 0.58 |
| 2021 | 0.66 | 0.96 | 0.4 |
| 2020 | 0.58 | 0.68 | 0.48 |
| 2019 | 0.66 | 0.92 | 0.54 |
| 2018 | 1.35 | 2.3 | 0.58 |
| 2017 | 3.35 | 5.77 | 1.7 |
| 2016 | 5.25 | 7.45 | 3.89 |
| 2015 | 4.41 | 7.92 | 2.62 |
| 2014 | 2.68 | 3.64 | 1.49 |
| 2013 | 1.87 | 2.36 | 1.55 |
| 2012 | 2.55 | 3.73 | 1.69 |
| 2011 | 5.58 | 7.01 | 2.71 |
| 2010 | 5.89 | 7.79 | 4.67 |
| 2009 | 3.44 | 5.09 | 1.84 |
| 2008 | 2.89 | 5.04 | 1.44 |
| 2007 | 4.7 | 6.49 | 3.23 |