| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.48 | 0.56 | 0.41 |
| 2024 | 0.63 | 0.85 | 0.5 |
| 2023 | 0.44 | 0.66 | 0.32 |
| 2022 | 0.38 | 0.57 | 0.27 |
| 2021 | 0.52 | 0.78 | 0.36 |
| 2020 | 0.45 | 0.66 | 0.34 |
| 2019 | 0.56 | 0.98 | 0.37 |
| 2018 | 0.38 | 0.54 | 0.27 |
| 2017 | 0.68 | 1.06 | 0.43 |
| 2016 | 0.96 | 1.14 | 0.85 |
| 2015 | 1.19 | 1.6 | 0.75 |
| 2014 | 1.09 | 1.3 | 0.93 |
| 2013 | 0.85 | 1.23 | 0.72 |
| 2012 | 0.96 | 1.23 | 0.67 |
| 2011 | 1.33 | 1.92 | 0.95 |
| 2010 | 1.73 | 2.26 | 1.3 |
| 2009 | 1.61 | 2.33 | 0.81 |
| 2008 | 1.3 | 2.52 | 0.63 |
| 2007 | 2 | 2.93 | 1.4 |
| 2006 | 1 | 1.51 | 0.64 |
| 2005 | 0.46 | 0.82 | 0.24 |
| 2004 | 0.5 | 1.05 | 0.28 |