| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 5.91 | 6.36 | 5.48 |
| 2024 | 5.68 | 6.98 | 4.43 |
| 2023 | 5.21 | 6.03 | 4.43 |
| 2022 | 4.08 | 5.26 | 3.52 |
| 2021 | 4.62 | 8 | 3.61 |
| 2020 | 4.11 | 5.16 | 3.68 |
| 2019 | 4.78 | 5.41 | 4.17 |
| 2018 | 5.17 | 6.9 | 4.14 |
| 2017 | 8.02 | 9.06 | 6.43 |
| 2016 | 8.02 | 10.43 | 5.91 |
| 2015 | 7.15 | 9.42 | 4.83 |
| 2014 | 5.23 | 7.21 | 4.56 |
| 2013 | 5.44 | 6.54 | 4.47 |
| 2012 | 5.86 | 6.97 | 5.18 |
| 2011 | 8.38 | 12.41 | 5.76 |
| 2010 | 12.81 | 14.9 | 10.18 |
| 2009 | 11.52 | 16.03 | 8.03 |
| 2008 | 13.55 | 26.35 | 6.69 |
| 2007 | 21.99 | 30.98 | 12.83 |
| 2006 | 6.9 | 12.74 | 4.94 |
| 2005 | 4.7 | 5.75 | 3.45 |
| 2004 | 6.23 | 9.21 | 3.69 |