| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.64 | 0.69 | 0.6 |
| 2024 | 0.63 | 0.76 | 0.4 |
| 2023 | 0.69 | 0.89 | 0.6 |
| 2022 | 0.61 | 0.79 | 0.44 |
| 2021 | 0.53 | 0.6 | 0.44 |
| 2020 | 0.68 | 0.96 | 0.56 |
| 2019 | 0.71 | 0.93 | 0.6 |
| 2018 | 0.75 | 0.89 | 0.55 |
| 2017 | 1.21 | 1.53 | 0.8 |
| 2016 | 1.55 | 1.89 | 1.33 |
| 2015 | 1.95 | 2.82 | 1.32 |
| 2014 | 1.99 | 3.3 | 1.57 |
| 2013 | 1.78 | 2.58 | 1.39 |
| 2012 | 2.18 | 3.16 | 1.47 |
| 2011 | 3.19 | 3.84 | 2.58 |
| 2010 | 3.8 | 5.08 | 2.6 |
| 2009 | 11.19 | 46.84 | 2.25 |
| 2008 | 14.83 | 28 | 9.16 |
| 2007 | 7.75 | 11.71 | 3.86 |
| 2006 | 4.27 | 6.04 | 3.5 |
| 2005 | 4.23 | 5.31 | 3.21 |
| 2004 | 5.85 | 9.16 | 3.85 |