| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.6 | 0.62 | 0.58 |
| 2024 | 0.59 | 0.65 | 0.54 |
| 2023 | 0.63 | 0.76 | 0.46 |
| 2022 | 0.49 | 0.55 | 0.45 |
| 2021 | 0.55 | 0.68 | 0.43 |
| 2020 | 0.64 | 0.75 | 0.53 |
| 2019 | 0.64 | 0.77 | 0.52 |
| 2018 | 0.62 | 0.73 | 0.54 |
| 2017 | 0.87 | 1.05 | 0.71 |
| 2016 | 0.93 | 1.06 | 0.81 |
| 2015 | 0.84 | 1.32 | 0.58 |
| 2014 | 0.65 | 0.75 | 0.56 |
| 2013 | 0.68 | 0.85 | 0.6 |
| 2012 | 0.84 | 1.28 | 0.55 |
| 2011 | 1.56 | 2.09 | 1.23 |
| 2010 | 1.26 | 1.74 | 1.06 |
| 2009 | 0.86 | 1.23 | 0.6 |
| 2008 | 1.41 | 3.1 | 0.38 |
| 2007 | 3.31 | 6.31 | 1.77 |
| 2006 | 1.9 | 2.34 | 1.4 |
| 2005 | 0.55 | 1.5 | 0.25 |
| 2004 | 0.51 | 1.08 | 0.31 |