| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 5.72 | 6.23 | 5.27 |
| 2024 | 6 | 7.07 | 5.19 |
| 2023 | 7.26 | 8.5 | 6.49 |
| 2022 | 6.17 | 7.33 | 5.2 |
| 2021 | 5.5 | 5.87 | 5.14 |
| 2020 | 5.15 | 5.84 | 4.47 |
| 2019 | 5.51 | 6.76 | 4.84 |
| 2018 | 6.01 | 7.69 | 4.64 |
| 2017 | 8.58 | 9.88 | 7.31 |
| 2016 | 8.26 | 10.84 | 6.55 |
| 2015 | 12.34 | 17.56 | 7.57 |
| 2014 | 8.17 | 10.85 | 6.87 |
| 2013 | 9.67 | 13.52 | 7.47 |
| 2012 | 11.81 | 15.15 | 8.4 |
| 2011 | 15.65 | 22.12 | 9.35 |
| 2010 | 18.35 | 25.35 | 10.66 |
| 2009 | 8.13 | 10.79 | 5.36 |
| 2008 | 5.17 | 7.2 | 2.86 |
| 2007 | 5.95 | 8.73 | 3.14 |
| 2006 | 2.16 | 3.25 | 1.07 |
| 2005 | 0.94 | 1.22 | 0.59 |
| 2004 | 0.93 | 1.39 | 0.73 |