| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.42 | 0.47 | 0.36 |
| 2024 | 0.5 | 0.68 | 0.39 |
| 2023 | 0.5 | 0.6 | 0.37 |
| 2022 | 0.6 | 1.11 | 0.34 |
| 2021 | 1.69 | 12.38 | 0.89 |
| 2020 | 1.73 | 2.71 | 1.06 |
| 2019 | 1.31 | 1.77 | 0.97 |
| 2018 | 1.3 | 2.04 | 0.92 |
| 2017 | 2.06 | 3.04 | 1.23 |
| 2016 | 1.16 | 1.35 | 0.95 |
| 2015 | 1.43 | 2.1 | 0.95 |
| 2014 | 0.78 | 1.32 | 0.6 |
| 2013 | 0.84 | 1.18 | 0.62 |
| 2012 | 1.08 | 1.57 | 0.74 |
| 2011 | 2.06 | 3.5 | 0.91 |
| 2010 | 2 | 2.6 | 1.26 |
| 2009 | 1.27 | 1.73 | 1.01 |
| 2008 | 1.16 | 1.86 | 0.62 |
| 2007 | 1.06 | 1.64 | 0.59 |
| 2006 | 0.47 | 0.63 | 0.35 |
| 2005 | 0.32 | 0.42 | 0.24 |
| 2004 | 0.61 | 1.48 | 0.26 |