| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.56 | 0.92 | 0.34 |
| 2024 | 0.37 | 0.44 | 0.31 |
| 2023 | 0.52 | 0.66 | 0.43 |
| 2022 | 0.74 | 0.9 | 0.58 |
| 2021 | 0.95 | 1.29 | 0.7 |
| 2020 | 0.84 | 1.06 | 0.74 |
| 2019 | 0.92 | 1.34 | 0.67 |
| 2018 | 1.21 | 1.87 | 0.86 |
| 2017 | 1.32 | 2 | 0.87 |
| 2016 | 0.93 | 1.35 | 0.6 |
| 2015 | 0.9 | 1.82 | 0.53 |
| 2014 | 0.39 | 0.63 | 0.32 |
| 2013 | 0.41 | 0.63 | 0.33 |
| 2012 | 0.4 | 0.49 | 0.33 |
| 2011 | 0.62 | 0.81 | 0.38 |
| 2010 | 0.6 | 0.81 | 0.36 |
| 2009 | 0.41 | 0.66 | 0.14 |
| 2008 | 0.29 | 0.68 | 0.09 |
| 2007 | 1.32 | 2.63 | 0.5 |
| 2006 | 0.5 | 0.89 | 0.38 |
| 2005 | 0.64 | 0.96 | 0.35 |
| 2004 | 0.98 | 2.14 | 0.55 |