| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.3 | 2.78 | 2.15 |
| 2024 | 1.99 | 3.06 | 1.3 |
| 2023 | 2.86 | 3.46 | 2.35 |
| 2022 | 3.16 | 3.83 | 2.74 |
| 2021 | 3.06 | 3.42 | 2.77 |
| 2020 | 3.26 | 4.14 | 2.53 |
| 2019 | 3.21 | 3.72 | 2.64 |
| 2018 | 3.13 | 4.1 | 2.46 |
| 2017 | 4.91 | 6.61 | 3.91 |
| 2016 | 6.02 | 7.33 | 5.04 |
| 2015 | 6.3 | 10.43 | 4.38 |
| 2014 | 4.43 | 5.46 | 3.76 |
| 2013 | 4.62 | 6.37 | 3.47 |
| 2012 | 6.79 | 9.16 | 4.52 |
| 2011 | 10 | 13.91 | 7.45 |
| 2010 | 12.3 | 15.54 | 8.53 |
| 2009 | 9.92 | 15.12 | 5.4 |
| 2008 | 9.06 | 16.47 | 4.6 |
| 2007 | 9.17 | 14.95 | 5.05 |
| 2006 | 3.32 | 5.33 | 2.11 |
| 2005 | 2.98 | 3.71 | 2.17 |