| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.97 | 2.38 | 1.69 |
| 2024 | 1.95 | 3.04 | 1.46 |
| 2023 | 2.05 | 2.26 | 1.82 |
| 2022 | 2.03 | 2.55 | 1.73 |
| 2021 | 2.16 | 2.94 | 1.84 |
| 2020 | 2.32 | 2.96 | 1.86 |
| 2019 | 2.46 | 3.84 | 1.86 |
| 2018 | 3.34 | 4.68 | 2.17 |
| 2017 | 6.65 | 9.47 | 4.22 |
| 2016 | 7.31 | 10.18 | 5.47 |
| 2015 | 15.6 | 32.16 | 7.18 |
| 2014 | 5.37 | 8.3 | 3.58 |
| 2013 | 4.62 | 7.16 | 3.44 |
| 2012 | 3.94 | 7.34 | 2.68 |
| 2011 | 4.99 | 7.29 | 2.79 |
| 2010 | 6.12 | 7.85 | 4.77 |
| 2009 | 4.72 | 6.32 | 2.14 |
| 2008 | 3.05 | 4.93 | 1.38 |
| 2007 | 4.51 | 8.09 | 2.4 |
| 2006 | 2.42 | 3.43 | 1.9 |
| 2005 | 2.28 | 3.54 | 1.52 |
| 2004 | 7.42 | 11.96 | 2.08 |