| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.86 | 0.95 | 0.8 |
| 2024 | 0.83 | 1 | 0.72 |
| 2023 | 0.93 | 1.05 | 0.78 |
| 2022 | 0.85 | 1.03 | 0.71 |
| 2021 | 1.39 | 1.79 | 0.95 |
| 2020 | 1.56 | 1.82 | 1.38 |
| 2019 | 2.13 | 2.87 | 1.59 |
| 2018 | 3.6 | 4.78 | 2.28 |
| 2017 | 4.25 | 5.85 | 2.59 |
| 2016 | 2.36 | 2.93 | 1.8 |
| 2015 | 3.3 | 5.16 | 1.7 |
| 2014 | 3.23 | 5.21 | 2.58 |
| 2013 | 4.27 | 6.44 | 2.67 |
| 2012 | 6.32 | 9.4 | 4.27 |
| 2011 | 10.85 | 17.25 | 5.14 |
| 2010 | 8.93 | 17.26 | 5.06 |
| 2009 | 2.72 | 6.22 | 0.81 |
| 2008 | 3.47 | 10.3 | 0.6 |
| 2007 | 15.07 | 23.73 | 8.15 |
| 2006 | 10.14 | 12.91 | 6.38 |
| 2005 | 7.15 | 11.64 | 5.54 |
| 2004 | 11.92 | 20.69 | 7.43 |