| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.75 | 0.94 | 0.66 |
| 2024 | 0.66 | 0.89 | 0.52 |
| 2023 | 0.84 | 1.11 | 0.73 |
| 2022 | 0.8 | 1.17 | 0.64 |
| 2021 | 0.77 | 1.1 | 0.68 |
| 2020 | 0.68 | 0.95 | 0.52 |
| 2019 | 0.88 | 1.63 | 0.57 |
| 2018 | 2.14 | 2.68 | 1.03 |
| 2017 | 4.41 | 7.46 | 2.64 |
| 2016 | 4.91 | 6.07 | 4.06 |
| 2015 | 4.94 | 10.21 | 2.95 |
| 2014 | 2.35 | 3.39 | 1.26 |
| 2013 | 1.13 | 1.44 | 0.86 |
| 2012 | 0.96 | 1.2 | 0.69 |
| 2011 | 1.2 | 1.75 | 0.74 |
| 2010 | 1.44 | 1.93 | 1.06 |
| 2009 | 1.03 | 1.68 | 0.42 |
| 2008 | 0.73 | 1.34 | 0.32 |
| 2007 | 1.53 | 2.31 | 0.93 |
| 2006 | 1.05 | 1.52 | 0.76 |
| 2005 | 1.03 | 1.18 | 0.88 |