| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.14 | 1.53 | 0.91 |
| 2024 | 0.91 | 1.34 | 0.7 |
| 2023 | 1.07 | 1.73 | 0.73 |
| 2022 | 1.8 | 2.4 | 1.18 |
| 2021 | 2.96 | 5.87 | 1.74 |
| 2020 | 1.69 | 2.52 | 1.07 |
| 2019 | 1.11 | 1.84 | 0.83 |
| 2018 | 1.48 | 2.3 | 0.92 |
| 2017 | 2.92 | 3.84 | 2.14 |
| 2016 | 4.11 | 5.37 | 3.59 |
| 2015 | 5.66 | 8.58 | 3.19 |
| 2014 | 3.9 | 5.6 | 2.72 |
| 2013 | 2.85 | 3.6 | 2.08 |
| 2012 | 2.84 | 4.44 | 1.8 |
| 2011 | 6.13 | 8.47 | 3.33 |
| 2010 | 4.04 | 6.56 | 2.57 |
| 2009 | 3.53 | 4.68 | 1.48 |
| 2008 | 3.81 | 7.79 | 1.22 |
| 2007 | 4.49 | 7.4 | 1.7 |
| 2006 | 1.64 | 1.98 | 1.34 |
| 2005 | 1.41 | 1.74 | 1.09 |
| 2004 | 2.2 | 3.37 | 1.42 |