| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.3 | 1.5 | 1.23 |
| 2024 | 1.17 | 1.57 | 0.88 |
| 2023 | 1.96 | 2.96 | 1.34 |
| 2022 | 2.59 | 4.51 | 1.25 |
| 2021 | 1.37 | 1.85 | 1.09 |
| 2020 | 1.05 | 1.94 | 0.55 |
| 2019 | 0.86 | 1.38 | 0.55 |
| 2018 | 0.86 | 1.08 | 0.61 |
| 2017 | 1.26 | 1.87 | 0.87 |
| 2016 | 1.35 | 2.02 | 1.06 |
| 2015 | 1.88 | 2.88 | 1.17 |
| 2014 | 1.18 | 1.81 | 0.95 |
| 2013 | 1.16 | 1.57 | 0.83 |
| 2012 | 1.79 | 2.66 | 1.16 |
| 2011 | 2.4 | 2.7 | 2.13 |
| 2010 | 4.18 | 4.6 | 3.69 |
| 2009 | 3.97 | 5.41 | 1.95 |
| 2008 | 3.13 | 5.71 | 1.43 |
| 2007 | 3.76 | 6.03 | 0.84 |
| 2006 | 0.62 | 0.91 | 0.37 |
| 2005 | 0.43 | 0.67 | 0.3 |
| 2004 | 0.52 | 0.63 | 0.34 |