| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.67 | 0.79 | 0.5 |
| 2024 | 0.63 | 0.96 | 0.43 |
| 2023 | 0.75 | 0.88 | 0.61 |
| 2022 | 0.99 | 1.41 | 0.7 |
| 2021 | 0.92 | 1.53 | 0.59 |
| 2020 | 0.7 | 1.01 | 0.49 |
| 2019 | 0.37 | 0.77 | 0.24 |
| 2018 | 0.51 | 0.77 | 0.28 |
| 2017 | 0.75 | 1.11 | 0.58 |
| 2016 | 0.89 | 1.34 | 0.72 |
| 2015 | 1.3 | 2.16 | 0.77 |
| 2014 | 0.73 | 1.14 | 0.54 |
| 2013 | 0.6 | 0.69 | 0.49 |
| 2012 | 0.69 | 0.84 | 0.56 |
| 2011 | 1.31 | 1.87 | 0.65 |
| 2010 | 2.04 | 3.37 | 1.49 |
| 2009 | 1.75 | 3.23 | 0.61 |
| 2008 | 1.8 | 4.57 | 0.5 |
| 2007 | 3.13 | 6.2 | 0.67 |
| 2006 | 0.54 | 0.78 | 0.31 |
| 2005 | 0.41 | 0.64 | 0.27 |
| 2004 | 1.53 | 3.35 | 0.64 |