| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1 | 1.31 | 0.87 |
| 2024 | 1.11 | 1.49 | 0.84 |
| 2023 | 1.12 | 1.31 | 0.95 |
| 2022 | 1.03 | 1.41 | 0.73 |
| 2021 | 1.86 | 3.06 | 1.04 |
| 2020 | 1.53 | 3.02 | 1.05 |
| 2019 | 1.55 | 1.99 | 1.26 |
| 2018 | 1.71 | 2.6 | 1.16 |
| 2017 | 18.34 | 49.87 | 2.21 |
| 2016 | 8.32 | 15.36 | 5.91 |
| 2015 | 8.39 | 18.91 | 3.66 |
| 2014 | 3.17 | 4.65 | 1.88 |
| 2013 | 1.84 | 2.22 | 1.61 |
| 2012 | 1.92 | 2.57 | 1.38 |
| 2011 | 3.06 | 4.21 | 1.78 |
| 2010 | 3.4 | 4.77 | 2.55 |
| 2009 | 2.83 | 3.82 | 1.82 |
| 2008 | 3.66 | 9.09 | 1.12 |
| 2007 | 6.76 | 10.82 | 2.38 |
| 2006 | 1.81 | 2.44 | 1.07 |
| 2005 | 1.21 | 2.08 | 0.77 |
| 2004 | 3.85 | 5.22 | 1.69 |
| 2003 | 3.5 | 4.49 | 2.75 |
| 2002 | 3.86 | 4.27 | 3.03 |
| 2001 | 5.16 | 6.19 | 3.75 |
| 2000 | 4.6 | 5.66 | 3.46 |