| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.96 | 2.72 | 1.52 |
| 2024 | 1.67 | 2.33 | 1.2 |
| 2023 | 2.71 | 3.24 | 2.21 |
| 2022 | 2.34 | 3.46 | 1.72 |
| 2021 | 5.37 | 11.1 | 2.96 |
| 2020 | 6.94 | 10.19 | 4.73 |
| 2019 | 5.61 | 7.06 | 4.33 |
| 2018 | 9.86 | 16.87 | 4.91 |
| 2017 | 11.71 | 14.01 | 10.04 |
| 2016 | 17 | 25.08 | 11.08 |
| 2015 | 20.03 | 51.03 | 2.89 |
| 2014 | 2.33 | 3.08 | 1.73 |
| 2013 | 2.28 | 2.71 | 1.82 |
| 2012 | 2.59 | 3.21 | 1.91 |
| 2011 | 4.45 | 5.86 | 2.7 |
| 2010 | 3.14 | 5.04 | 2.22 |
| 2009 | 2.32 | 3.07 | 1.42 |
| 2008 | 1.71 | 2.77 | 0.91 |
| 2007 | 1.66 | 2.2 | 0.96 |
| 2006 | 0.92 | 1.01 | 0.76 |