| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.25 | 1.74 | 1.05 |
| 2024 | 1.11 | 1.4 | 0.86 |
| 2023 | 1.36 | 1.61 | 1.13 |
| 2022 | 1.69 | 2.26 | 1.38 |
| 2021 | 1.38 | 1.83 | 0.97 |
| 2020 | 1.21 | 1.98 | 0.91 |
| 2019 | 1.14 | 1.44 | 0.94 |
| 2018 | 1.39 | 1.68 | 1.14 |
| 2017 | 1.73 | 1.88 | 1.54 |
| 2016 | 1.72 | 2.32 | 1.19 |
| 2015 | 1.71 | 2.82 | 1.13 |
| 2014 | 1.38 | 1.74 | 1.16 |
| 2013 | 2.85 | 5.52 | 1.57 |
| 2012 | 3.92 | 5.06 | 2.65 |
| 2011 | 14.33 | 76.62 | 3.98 |
| 2010 | 9.52 | 15.76 | 5.47 |
| 2009 | 3.84 | 5.47 | 2.32 |
| 2008 | 3.63 | 7.3 | 1.8 |
| 2007 | 5.82 | 8.3 | 2.99 |
| 2006 | 3.03 | 4.04 | 2.46 |
| 2005 | 4.4 | 7.33 | 2.89 |
| 2004 | 5.08 | 5.86 | 2.75 |