| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.03 | 1.14 | 0.94 |
| 2024 | 1 | 1.16 | 0.77 |
| 2023 | 1.02 | 1.26 | 0.82 |
| 2022 | 1.62 | 2.21 | 1.1 |
| 2021 | 2.24 | 3.16 | 1.73 |
| 2020 | 1.44 | 2.21 | 0.87 |
| 2019 | 1.26 | 1.46 | 1.02 |
| 2018 | 1.29 | 1.56 | 1.09 |
| 2017 | 1.49 | 1.87 | 1.31 |
| 2016 | 1.76 | 2.02 | 1.48 |
| 2015 | 1.78 | 2.56 | 1.28 |
| 2014 | 1.71 | 3.84 | 1.16 |
| 2013 | 1.42 | 1.82 | 1.16 |
| 2012 | 1.1 | 1.37 | 0.68 |
| 2011 | 1.43 | 1.92 | 0.72 |
| 2010 | 1.26 | 1.65 | 0.9 |
| 2009 | 0.68 | 1.17 | 0.3 |
| 2008 | 0.51 | 0.98 | 0.24 |
| 2007 | 0.8 | 1.27 | 0.46 |
| 2006 | 0.48 | 0.64 | 0.35 |
| 2005 | 0.44 | 0.58 | 0.27 |
| 2004 | 1.31 | 2.82 | 0.53 |