| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 1.71 | 2.72 | 1.22 |
| 2023 | 2.45 | 3.38 | 1.57 |
| 2022 | 4.84 | 6.88 | 3.02 |
| 2021 | 6.54 | 9.99 | 4.57 |
| 2020 | 4.1 | 7.5 | 2.53 |
| 2019 | 3.2 | 4 | 2.15 |
| 2018 | 2.51 | 3.95 | 1.44 |
| 2017 | 2.66 | 4.28 | 1.71 |
| 2016 | 3.66 | 5.83 | 2.25 |
| 2015 | 4.47 | 8.32 | 3.3 |
| 2014 | 3.43 | 4 | 2.87 |
| 2013 | 2.93 | 4.08 | 2.46 |
| 2012 | 2.79 | 3.94 | 2.19 |
| 2011 | 3.96 | 4.92 | 2.27 |
| 2010 | 5.42 | 7.09 | 4.2 |
| 2009 | 5.75 | 7.24 | 4.31 |
| 2008 | 9.28 | 18.79 | 2.73 |
| 2007 | 9.49 | 14.57 | 5.36 |
| 2006 | 3.85 | 5.63 | 2.86 |
| 2005 | 2.51 | 2.92 | 2 |