| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.87 | 0.95 | 0.78 |
| 2024 | 0.82 | 1 | 0.61 |
| 2023 | 0.3 | 0.75 | 0.07 |
| 2022 | 0.58 | 0.7 | 0.42 |
| 2021 | 0.38 | 0.53 | 0.28 |
| 2020 | 0.39 | 0.47 | 0.29 |
| 2019 | 0.58 | 0.73 | 0.38 |
| 2018 | 0.75 | 0.92 | 0.62 |
| 2017 | 0.99 | 1.35 | 0.79 |
| 2016 | 0.93 | 1.22 | 0.76 |
| 2015 | 1.01 | 1.51 | 0.68 |
| 2014 | 1.16 | 1.46 | 0.94 |
| 2013 | 1.58 | 1.97 | 1.21 |
| 2012 | 2.59 | 3.27 | 1.78 |
| 2011 | 3.95 | 5.04 | 2.81 |
| 2010 | 4.33 | 5.35 | 3.35 |
| 2009 | 2.55 | 3.89 | 1.64 |
| 2008 | 4.95 | 11.69 | 1.06 |
| 2007 | 5.46 | 12.34 | 1.57 |
| 2006 | 1.2 | 1.55 | 0.92 |
| 2005 | 0.21 | 0.91 | 0.04 |
| 2004 | 0.05 | 0.06 | 0.04 |