| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.07 | 1.51 | 0.9 |
| 2024 | 0.89 | 1.09 | 0.73 |
| 2023 | 1.05 | 1.37 | 0.8 |
| 2022 | 1.39 | 1.82 | 1.06 |
| 2021 | 2.15 | 2.88 | 1.72 |
| 2020 | 2.4 | 3.2 | 1.87 |
| 2019 | 2.1 | 2.4 | 1.9 |
| 2018 | 2.44 | 3.26 | 1.88 |
| 2017 | 3.47 | 4.29 | 3.06 |
| 2016 | 4.31 | 6.49 | 3.6 |
| 2015 | 5 | 7.89 | 3.28 |
| 2014 | 3.73 | 4.75 | 2.81 |
| 2013 | 2.81 | 3.41 | 2.32 |
| 2012 | 3.56 | 4.5 | 2.56 |
| 2011 | 6.57 | 9.47 | 4.02 |
| 2010 | 8.12 | 11.7 | 5.54 |
| 2009 | 4.51 | 5.98 | 2.45 |
| 2008 | 4.57 | 9.14 | 2.05 |
| 2007 | 6.99 | 10.29 | 2.82 |
| 2006 | 2.92 | 3.5 | 2.53 |
| 2005 | 2.51 | 3.12 | 1.82 |
| 2004 | 2.71 | 4.06 | 1.95 |