| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.07 | 1.22 | 0.94 |
| 2024 | 0.79 | 1.95 | 0.41 |
| 2023 | 0.57 | 0.64 | 0.52 |
| 2022 | 0.58 | 0.89 | 0.47 |
| 2021 | 0.83 | 1.07 | 0.7 |
| 2020 | 0.99 | 1.37 | 0.8 |
| 2019 | 1.21 | 1.47 | 1.02 |
| 2018 | 1.63 | 2.43 | 1.09 |
| 2017 | 3.25 | 4.37 | 2.32 |
| 2016 | 7.72 | 19.18 | 3.71 |
| 2015 | 13.05 | 26.24 | 3.02 |
| 2014 | 4.01 | 5.59 | 2.86 |
| 2013 | 3.8 | 6.84 | 2.2 |
| 2012 | 5.37 | 7.36 | 3.79 |
| 2011 | 9.02 | 14.39 | 3.58 |
| 2010 | 3.57 | 4.83 | 2.46 |
| 2009 | 1.81 | 5.26 | 0.65 |
| 2008 | 1.12 | 2.49 | 0.52 |
| 2007 | 1.97 | 2.79 | 1.05 |
| 2006 | 0.72 | 1.19 | 0.43 |
| 2005 | 0.6 | 1.18 | 0.38 |
| 2004 | 3.55 | 7.53 | 1.12 |