| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.62 | 1.79 | 1.46 |
| 2024 | 1.51 | 2.17 | 1.15 |
| 2023 | 2.05 | 2.62 | 1.67 |
| 2022 | 1.79 | 2.7 | 1.32 |
| 2021 | 1.96 | 2.31 | 1.69 |
| 2020 | 2.01 | 2.88 | 1.54 |
| 2019 | 2.25 | 3.06 | 1.85 |
| 2018 | 2.67 | 3.68 | 1.94 |
| 2017 | 4.95 | 7.52 | 3.48 |
| 2016 | 5.32 | 6.72 | 3.39 |
| 2015 | 5.18 | 9.09 | 3.04 |
| 2014 | 4.33 | 5.41 | 3.22 |
| 2013 | 3.98 | 5.32 | 2.8 |
| 2012 | 3.64 | 5.32 | 2.44 |
| 2011 | 5.74 | 8.52 | 4.03 |
| 2010 | 7.6 | 12.43 | 4.49 |
| 2009 | 6.67 | 12.07 | 2.37 |
| 2008 | 3.18 | 5.91 | 1.76 |
| 2007 | 3.58 | 4.83 | 2.16 |
| 2006 | 3.41 | 5.23 | 2.03 |
| 2005 | 2.22 | 3.22 | 1.21 |
| 2004 | 2.27 | 2.91 | 1.81 |