| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.42 | 2.78 | 2.2 |
| 2024 | 2.47 | 3.3 | 1.69 |
| 2023 | 1.93 | 2.37 | 1.57 |
| 2022 | 1.48 | 1.77 | 1.32 |
| 2021 | 1.74 | 2.1 | 1.57 |
| 2020 | 2.44 | 3.6 | 1.82 |
| 2019 | 2.23 | 2.63 | 1.95 |
| 2018 | 2.07 | 2.62 | 1.63 |
| 2017 | 2.83 | 3.39 | 2.37 |
| 2016 | 3.51 | 5.51 | 2.31 |
| 2015 | 3.38 | 4.95 | 2.43 |
| 2014 | 2.42 | 3.16 | 2.17 |
| 2013 | 3.41 | 5.25 | 2.33 |
| 2012 | 5.01 | 5.78 | 3.87 |
| 2011 | 9.04 | 12.44 | 3.97 |
| 2010 | 11.2 | 15.21 | 8.74 |
| 2009 | 8.78 | 13.6 | 3.25 |
| 2008 | 12.85 | 44.05 | 2.12 |
| 2007 | 21.16 | 47.43 | 5.85 |
| 2006 | 6.19 | 10.27 | 2.95 |
| 2005 | 2.46 | 2.8 | 2.13 |
| 2004 | 2.78 | 3.9 | 2.08 |