| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.54 | 1.72 | 1.39 |
| 2024 | 1.6 | 1.94 | 1.31 |
| 2023 | 2.24 | 3.32 | 1.68 |
| 2022 | 2.84 | 4.27 | 2.12 |
| 2021 | 3.62 | 4.78 | 2.59 |
| 2020 | 2.85 | 4.2 | 1.8 |
| 2019 | 2.5 | 5.12 | 1.88 |
| 2018 | 2.21 | 3.14 | 1.57 |
| 2017 | 3.21 | 3.8 | 2.68 |
| 2016 | 3.28 | 5.01 | 1.94 |
| 2015 | 3.19 | 4.88 | 1.89 |
| 2014 | 2.52 | 3.06 | 2.1 |
| 2013 | 2.74 | 4.52 | 1.97 |
| 2012 | 3.09 | 3.75 | 2.54 |
| 2011 | 5.6 | 7.73 | 2.81 |
| 2010 | 5.69 | 8.85 | 3.97 |
| 2009 | 4.86 | 8.03 | 1.66 |
| 2008 | 3.97 | 9.65 | 1.2 |
| 2007 | 8.33 | 13.3 | 3.28 |
| 2006 | 2.36 | 3.9 | 1.35 |
| 2005 | 1.49 | 2.07 | 1.06 |
| 2004 | 2.15 | 3.07 | 1.7 |