| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 5.75 | 5.93 | 5.59 |
| 2024 | 6.31 | 7.57 | 4.73 |
| 2023 | 8.88 | 12.16 | 6.35 |
| 2022 | 9.92 | 13.46 | 7.46 |
| 2021 | 17.19 | 24.08 | 11.89 |
| 2020 | 14.04 | 20.41 | 8.28 |
| 2019 | 9.51 | 12.6 | 5.07 |
| 2018 | 8.1 | 12.08 | 4.92 |
| 2017 | 7.64 | 10.82 | 5.43 |
| 2016 | 5.1 | 6.08 | 4.05 |
| 2015 | 4.61 | 5.93 | 3.74 |
| 2014 | 2.97 | 4 | 2.18 |
| 2013 | 2.96 | 4.23 | 2.22 |
| 2012 | 5.61 | 7.19 | 3.57 |
| 2011 | 7.8 | 9.03 | 6.16 |
| 2010 | 9.54 | 12.98 | 7.28 |
| 2009 | 9.14 | 13.03 | 6.63 |
| 2008 | 11.74 | 23.78 | 5.8 |
| 2007 | 15.47 | 26.42 | 8.38 |
| 2006 | 4.76 | 8.37 | 2.73 |
| 2005 | 2.87 | 3.54 | 1.64 |
| 2004 | 2.05 | 3.31 | 1.62 |