| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 6.67 | 7.76 | 6.01 |
| 2024 | 6.4 | 8.4 | 4.89 |
| 2023 | 8.03 | 12 | 6.34 |
| 2022 | 10.54 | 17.35 | 6.95 |
| 2021 | 14.33 | 24.01 | 7.59 |
| 2020 | 9.41 | 11.63 | 7.37 |
| 2019 | 6.28 | 9.82 | 3.93 |
| 2018 | 6.44 | 10.9 | 4.23 |
| 2017 | 7.88 | 10.99 | 6.13 |
| 2016 | 6.35 | 9.44 | 4.05 |
| 2015 | 3.71 | 5.48 | 2.1 |
| 2014 | 2.03 | 2.92 | 1.47 |
| 2013 | 1.82 | 2.25 | 1.4 |
| 2012 | 2.36 | 2.91 | 1.8 |
| 2011 | 21.61 | 68.52 | 2.28 |
| 2010 | 35.25 | 63.25 | 18.33 |
| 2009 | 32.42 | 52.97 | 14.93 |
| 2008 | 25.85 | 43.72 | 12.06 |
| 2007 | 18.99 | 32.34 | 8.27 |
| 2006 | 6.48 | 9.48 | 3.85 |
| 2005 | 2.42 | 5.34 | 0.58 |
| 2004 | 1.57 | 2.52 | 0.98 |