| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.86 | 0.92 | 0.8 |
| 2024 | 0.68 | 0.9 | 0.49 |
| 2023 | 0.66 | 0.96 | 0.53 |
| 2022 | 0.92 | 1.18 | 0.6 |
| 2021 | 1.44 | 2.04 | 1.06 |
| 2020 | 1.12 | 1.45 | 0.84 |
| 2019 | 1.01 | 1.25 | 0.88 |
| 2018 | 1.51 | 2.26 | 0.93 |
| 2017 | 2.84 | 3.95 | 1.9 |
| 2016 | 3.26 | 4.61 | 1.36 |
| 2015 | 2.53 | 3.87 | 1.49 |
| 2014 | 1.97 | 2.81 | 1.61 |
| 2013 | 2.55 | 3.3 | 1.98 |
| 2012 | 2.41 | 3.11 | 1.65 |
| 2011 | 3.96 | 6.51 | 1.69 |
| 2010 | 2.9 | 5.12 | 1.68 |
| 2009 | 2.73 | 4.63 | 1.12 |
| 2008 | 1.77 | 3.85 | 1.03 |
| 2007 | 2.96 | 4.49 | 1.97 |
| 2006 | 1.94 | 2.86 | 1.41 |
| 2005 | 1.32 | 1.91 | 1.05 |
| 2004 | 1.86 | 3.66 | 1.02 |