| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.83 | 3.03 | 0.97 |
| 2024 | 1.02 | 1.42 | 0.62 |
| 2023 | 1.46 | 1.71 | 1.3 |
| 2022 | 1.42 | 1.86 | 1.16 |
| 2021 | 1.51 | 1.84 | 1.3 |
| 2020 | 2.28 | 3.11 | 1.73 |
| 2019 | 2.34 | 3.25 | 1.33 |
| 2018 | 1.39 | 1.81 | 0.89 |
| 2017 | 2.51 | 3.45 | 1.73 |
| 2016 | 3.16 | 3.81 | 2.14 |
| 2015 | 3.86 | 6.57 | 2.35 |
| 2014 | 2.31 | 2.74 | 2.01 |
| 2013 | 2.41 | 2.81 | 2.08 |
| 2012 | 3.14 | 4.59 | 1.91 |
| 2011 | 4.8 | 6.09 | 4 |
| 2010 | 5.57 | 6.47 | 4.09 |
| 2009 | 3.75 | 4.55 | 2.78 |
| 2008 | 8.03 | 25.72 | 1.9 |
| 2007 | 18.69 | 27.55 | 7.51 |
| 2006 | 6.49 | 8.79 | 4.04 |
| 2005 | 3.82 | 4.74 | 2.68 |
| 2004 | 6.11 | 10.92 | 2.99 |