| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 8.26 | 11.1 | 6.24 |
| 2024 | 7.77 | 12.12 | 5.17 |
| 2023 | 9.87 | 13.19 | 6.9 |
| 2022 | 7.43 | 8.81 | 6.25 |
| 2021 | 5.55 | 7.47 | 3.34 |
| 2020 | 4.5 | 5.48 | 2.73 |
| 2019 | 5.52 | 8.9 | 4.06 |
| 2018 | 11.13 | 23.58 | 5.1 |
| 2017 | 30.47 | 38.54 | 21.33 |
| 2016 | 37.67 | 46.7 | 28.93 |
| 2015 | 22.31 | 30.72 | 9.59 |
| 2014 | 7.58 | 11.33 | 5.02 |
| 2013 | 5.96 | 7.17 | 4.07 |
| 2012 | 4.43 | 5.78 | 3.35 |
| 2011 | 5.49 | 7.67 | 3.53 |
| 2010 | 6.6 | 8.4 | 5.33 |
| 2009 | 4.3 | 5.91 | 2.5 |
| 2008 | 3.4 | 6.45 | 1.58 |
| 2007 | 4.47 | 6.37 | 2.64 |
| 2006 | 2.43 | 3.07 | 1.76 |
| 2005 | 1.8 | 2.37 | 1.38 |
| 2004 | 2.02 | 2.9 | 1.45 |