| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.58 | 0.61 | 0.55 |
| 2024 | 0.6 | 0.7 | 0.5 |
| 2023 | 0.73 | 1.01 | 0.55 |
| 2022 | 0.9 | 1.33 | 0.7 |
| 2021 | 0.84 | 1.51 | 0.68 |
| 2020 | 0.82 | 0.92 | 0.74 |
| 2019 | 0.97 | 1.16 | 0.78 |
| 2018 | 0.97 | 1.26 | 0.77 |
| 2017 | 1.53 | 1.81 | 1.12 |
| 2016 | 1.44 | 1.84 | 1.15 |
| 2015 | 2.32 | 4.36 | 1.12 |
| 2014 | 0.72 | 1.18 | 0.61 |
| 2013 | 0.66 | 0.86 | 0.56 |
| 2012 | 0.64 | 0.72 | 0.54 |
| 2011 | 0.64 | 0.81 | 0.52 |
| 2010 | 0.83 | 1.26 | 0.56 |
| 2009 | 1.16 | 1.54 | 0.74 |
| 2008 | 1.31 | 2.27 | 0.67 |
| 2007 | 1.68 | 2.24 | 0.91 |
| 2006 | 0.87 | 1.04 | 0.79 |
| 2005 | 1.18 | 1.68 | 0.81 |
| 2004 | 1.69 | 2.91 | 1.1 |