| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.43 | 2.06 | 1.16 |
| 2024 | 1.05 | 1.49 | 0.88 |
| 2023 | 1.1 | 1.27 | 0.92 |
| 2022 | 1.15 | 1.63 | 0.9 |
| 2021 | 1.48 | 2.55 | 0.86 |
| 2020 | 0.84 | 0.97 | 0.73 |
| 2019 | 1.07 | 1.41 | 0.85 |
| 2018 | 1.57 | 2.53 | 1 |
| 2017 | 3.2 | 4.22 | 2.39 |
| 2016 | 4.07 | 4.75 | 3.42 |
| 2015 | 4.33 | 7.72 | 2 |
| 2014 | 1.13 | 2.33 | 0.78 |
| 2013 | 0.93 | 1.15 | 0.81 |
| 2012 | 0.84 | 1.03 | 0.6 |
| 2011 | 0.97 | 1.46 | 0.54 |
| 2010 | 0.68 | 0.91 | 0.55 |
| 2009 | 0.62 | 0.9 | 0.42 |
| 2008 | 1.1 | 2.43 | 0.33 |
| 2007 | 1.53 | 3.31 | 0.65 |
| 2006 | 0.44 | 0.61 | 0.33 |
| 2005 | 0.3 | 0.36 | 0.15 |
| 2004 | 0.39 | 0.73 | 0.23 |