| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.46 | 0.57 | 0.41 |
| 2024 | 0.37 | 0.63 | 0.27 |
| 2023 | 0.44 | 0.56 | 0.35 |
| 2022 | 0.6 | 0.87 | 0.47 |
| 2021 | 0.58 | 1.12 | 0.42 |
| 2020 | 0.4 | 0.52 | 0.29 |
| 2019 | 0.54 | 0.77 | 0.4 |
| 2018 | 0.51 | 0.68 | 0.4 |
| 2017 | 0.84 | 1.21 | 0.61 |
| 2016 | 0.8 | 1.26 | 0.56 |
| 2015 | 0.82 | 1.4 | 0.51 |
| 2014 | 0.57 | 0.66 | 0.51 |
| 2013 | 0.7 | 1 | 0.52 |
| 2012 | 1.24 | 1.85 | 0.78 |
| 2011 | 1.67 | 2.3 | 1.2 |
| 2010 | 1.27 | 1.93 | 0.82 |
| 2009 | 0.78 | 1.18 | 0.44 |
| 2008 | 1.14 | 2.53 | 0.33 |
| 2007 | 1.57 | 2.46 | 0.99 |
| 2006 | 1.08 | 1.36 | 0.91 |
| 2005 | 1.17 | 1.54 | 0.92 |