| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.85 | 2.53 | 1.46 |
| 2024 | 1.4 | 2.09 | 0.72 |
| 2023 | 0.93 | 1.32 | 0.74 |
| 2022 | 1.09 | 1.31 | 0.74 |
| 2021 | 1.22 | 1.98 | 0.85 |
| 2020 | 0.78 | 1.5 | 0.42 |
| 2019 | 0.72 | 1.08 | 0.52 |
| 2018 | 2.19 | 4.26 | 0.75 |
| 2017 | 5.16 | 7.09 | 3.31 |
| 2016 | 5.82 | 8.17 | 4.57 |
| 2015 | 7.88 | 16.03 | 5.68 |
| 2014 | 5.87 | 10.76 | 3.9 |
| 2013 | 8.14 | 19.22 | 3.95 |
| 2012 | 11.22 | 17 | 6.14 |
| 2011 | 4.97 | 7.32 | 3.07 |
| 2010 | 6.81 | 14.5 | 2.78 |
| 2009 | 8.74 | 15.74 | 3.74 |
| 2008 | 4.06 | 7.33 | 2.04 |
| 2007 | 5.85 | 10.23 | 3.02 |
| 2006 | 3.55 | 4.97 | 2.42 |
| 2005 | 1.95 | 2.71 | 1.22 |
| 2004 | 3.43 | 7.55 | 2.04 |