| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.5 | 4.16 | 3.04 |
| 2024 | 3.47 | 5.34 | 2.63 |
| 2023 | 3.19 | 3.97 | 2.68 |
| 2022 | 2.99 | 3.41 | 2.53 |
| 2021 | 3.93 | 5.17 | 2.6 |
| 2020 | 3.21 | 4.8 | 2.17 |
| 2019 | 3.23 | 5.5 | 1.95 |
| 2018 | 4.01 | 6.07 | 2.14 |
| 2017 | 8.22 | 11.03 | 5.08 |
| 2016 | 6.91 | 12.43 | 3.73 |
| 2015 | 6.39 | 11.38 | 3.7 |
| 2014 | 6.06 | 7.41 | 5.13 |
| 2013 | 7.33 | 9.95 | 5.2 |
| 2012 | 18.31 | 46.7 | 6.62 |
| 2011 | 45.74 | 65.63 | 32.57 |
| 2010 | 49.74 | 78.47 | 37.66 |
| 2009 | 22.15 | 47.85 | 6.13 |
| 2008 | 13.01 | 29.81 | 5.18 |
| 2007 | 437.84 | 1277.92 | 19.45 |
| 2006 | 156.89 | 289.34 | 18.3 |
| 2005 | 3.03 | 5.41 | 1.37 |
| 2004 | 3.97 | 6.55 | 2.89 |