| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.83 | 1.99 | 1.67 |
| 2024 | 1.65 | 2.21 | 1.15 |
| 2023 | 1.49 | 1.73 | 1.1 |
| 2022 | 1.1 | 1.41 | 0.89 |
| 2021 | 1.53 | 1.81 | 1.33 |
| 2020 | 1.44 | 1.71 | 1.2 |
| 2019 | 1.99 | 2.47 | 1.62 |
| 2018 | 2.64 | 3.47 | 1.82 |
| 2017 | 2.6 | 2.98 | 2.27 |
| 2016 | 3.08 | 3.79 | 2.72 |
| 2015 | 5.05 | 7.39 | 3.85 |
| 2014 | 10.58 | 33.63 | 3.16 |
| 2013 | 2.06 | 3.3 | 1.51 |
| 2012 | 1.69 | 2.08 | 1.45 |
| 2011 | 2.88 | 4.06 | 1.71 |
| 2010 | 3.45 | 4.22 | 2.91 |
| 2009 | 2.74 | 3.83 | 1.53 |
| 2008 | 1.98 | 2.88 | 1.2 |
| 2007 | 2.22 | 3.06 | 1.11 |
| 2006 | 1.1 | 1.29 | 1 |
| 2005 | 1.32 | 1.79 | 1.03 |
| 2004 | 1.87 | 3.34 | 1.27 |