| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.69 | 1.88 | 1.57 |
| 2024 | 1.57 | 2.14 | 1.14 |
| 2023 | 1.94 | 2.16 | 1.68 |
| 2022 | 2.14 | 4.03 | 1.59 |
| 2021 | 1.8 | 2.11 | 1.56 |
| 2020 | 1.76 | 2.07 | 1.46 |
| 2019 | 1.72 | 2.72 | 1.41 |
| 2018 | 1.82 | 2.39 | 1.31 |
| 2017 | 3.33 | 5 | 2.2 |
| 2016 | 3.9 | 5.1 | 2.62 |
| 2015 | 4.4 | 5.71 | 2.7 |
| 2014 | 4.02 | 5.63 | 3.18 |
| 2013 | 3.38 | 4.35 | 2 |
| 2012 | 1.97 | 2.36 | 1.53 |
| 2011 | 3.96 | 5.47 | 2.16 |
| 2010 | 5.35 | 7 | 3.22 |
| 2009 | 3.83 | 6.04 | 2.03 |
| 2008 | 2.53 | 4.24 | 1.62 |
| 2007 | 3.2 | 4.93 | 1.79 |
| 2006 | 1.63 | 2.24 | 1.2 |
| 2005 | 1.37 | 2 | 1.06 |
| 2004 | 2.16 | 3.84 | 1.3 |