| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.08 | 1.2 | 0.97 |
| 2024 | 0.94 | 1.46 | 0.76 |
| 2023 | 1.02 | 1.22 | 0.88 |
| 2022 | 1.34 | 1.66 | 1.13 |
| 2021 | 1.58 | 2.16 | 1.32 |
| 2020 | 0.82 | 1.45 | 0.69 |
| 2019 | 0.97 | 1.48 | 0.73 |
| 2018 | 1.21 | 1.8 | 0.72 |
| 2017 | 3.03 | 4.81 | 1.8 |
| 2016 | 4.69 | 5.58 | 4.05 |
| 2015 | 6.52 | 13.59 | 1.78 |
| 2014 | 1.3 | 2.19 | 0.73 |
| 2013 | 1.82 | 3.94 | 0.94 |
| 2012 | 5.35 | 13.07 | 2.19 |
| 2011 | 4.57 | 7.04 | 1.97 |
| 2010 | 2.45 | 4.3 | 1.77 |
| 2009 | 1.52 | 3.19 | 0.48 |
| 2008 | 1.2 | 3.2 | 0.42 |
| 2007 | 1.55 | 2.65 | 0.73 |
| 2006 | 0.93 | 1.38 | 0.55 |
| 2005 | 0.62 | 0.84 | 0.47 |
| 2004 | 0.78 | 0.98 | 0.57 |