| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.72 | 0.87 | 0.6 |
| 2024 | 0.6 | 0.83 | 0.44 |
| 2023 | 0.72 | 0.81 | 0.63 |
| 2022 | 0.84 | 1.05 | 0.7 |
| 2021 | 0.7 | 0.84 | 0.6 |
| 2020 | 0.68 | 0.77 | 0.6 |
| 2019 | 0.74 | 1 | 0.63 |
| 2018 | 0.74 | 1.01 | 0.57 |
| 2017 | 1.22 | 1.59 | 0.99 |
| 2016 | 1.39 | 1.72 | 1.17 |
| 2015 | 2.16 | 4.14 | 1.28 |
| 2014 | 1.9 | 2.76 | 1.55 |
| 2013 | 1.94 | 2.4 | 1.57 |
| 2012 | 2.77 | 3.84 | 1.34 |
| 2011 | 4.5 | 5.49 | 3.34 |
| 2010 | 3.79 | 5.09 | 2.87 |
| 2009 | 3.52 | 5.8 | 1.35 |
| 2008 | 2.15 | 3.76 | 1.02 |
| 2007 | 2.86 | 4.37 | 1.24 |
| 2006 | 1.52 | 2.1 | 1.16 |
| 2005 | 1.51 | 1.75 | 1.25 |