| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.41 | 1.54 | 1.32 |
| 2024 | 1.54 | 1.81 | 1.35 |
| 2023 | 1.33 | 1.74 | 0.99 |
| 2022 | 1.3 | 1.51 | 1.17 |
| 2021 | 1.31 | 1.56 | 1.15 |
| 2020 | 1.47 | 1.65 | 1.27 |
| 2019 | 1.78 | 2.88 | 1.4 |
| 2018 | 1.76 | 2.14 | 1.37 |
| 2017 | 2.39 | 2.99 | 1.91 |
| 2016 | 2.39 | 2.82 | 2.07 |
| 2015 | 3.42 | 6.3 | 2.19 |
| 2014 | 1.75 | 3.06 | 1.17 |
| 2013 | 1.43 | 1.92 | 1.13 |
| 2012 | 2 | 2.38 | 1.6 |
| 2011 | 2.92 | 3.72 | 2.13 |
| 2010 | 4.09 | 5.33 | 3.28 |
| 2009 | 4.18 | 5.12 | 3.03 |
| 2008 | 4.95 | 8.95 | 2.73 |
| 2007 | 7.87 | 10.36 | 4.73 |
| 2006 | 4.14 | 5.66 | 3.37 |
| 2005 | 5.32 | 6.72 | 3.97 |
| 2004 | 5.35 | 6.01 | 4.61 |