| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.96 | 1.39 | 0.75 |
| 2024 | 0.76 | 1.1 | 0.54 |
| 2023 | 0.9 | 1.14 | 0.79 |
| 2022 | 0.87 | 1.32 | 0.59 |
| 2021 | 0.75 | 0.9 | 0.62 |
| 2020 | 0.92 | 1.22 | 0.77 |
| 2019 | 0.97 | 1.4 | 0.78 |
| 2018 | 1.04 | 1.38 | 0.79 |
| 2017 | 1.04 | 1.35 | 0.84 |
| 2016 | 1.41 | 2.3 | 1.13 |
| 2015 | 1.72 | 3.31 | 0.86 |
| 2014 | 0.57 | 1 | 0.35 |
| 2013 | 0.34 | 0.45 | 0.28 |
| 2012 | 0.32 | 0.39 | 0.27 |
| 2011 | 0.5 | 0.66 | 0.33 |
| 2010 | 0.8 | 1.28 | 0.51 |
| 2009 | 0.88 | 1.44 | 0.32 |
| 2008 | 0.64 | 1.21 | 0.28 |
| 2007 | 0.78 | 1.33 | 0.36 |
| 2006 | 0.37 | 0.45 | 0.33 |
| 2005 | 0.46 | 1.07 | 0.3 |
| 2004 | 0.58 | 1.22 | 0.31 |