| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.77 | 2.19 | 1.55 |
| 2024 | 1.72 | 2.06 | 1.42 |
| 2023 | 1.73 | 1.96 | 1.53 |
| 2022 | 1.73 | 2.04 | 1.49 |
| 2021 | 1.72 | 2.17 | 1.44 |
| 2020 | 1.36 | 1.75 | 1.14 |
| 2019 | 1.63 | 2 | 1.36 |
| 2018 | 2.25 | 4.3 | 1.41 |
| 2017 | 3.21 | 4.09 | 2.45 |
| 2016 | 2.66 | 3.79 | 1.88 |
| 2015 | 2.85 | 4.63 | 1.93 |
| 2014 | 2.26 | 2.99 | 1.87 |
| 2013 | 3.86 | 5.98 | 2.14 |
| 2012 | 5.27 | 6.43 | 4.32 |
| 2011 | 6.65 | 8.88 | 4.69 |
| 2010 | 6.11 | 11.57 | 3.36 |
| 2009 | 7.54 | 11.92 | 3.1 |
| 2008 | 6.43 | 12.14 | 2.13 |
| 2007 | 12.38 | 18.47 | 6.63 |
| 2006 | 5.72 | 9.33 | 3 |
| 2005 | 2.49 | 2.93 | 2.1 |