| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0 | ||
| 2024 | 0 | ||
| 2023 | 0.46 | 0.62 | 0.26 |
| 2022 | 0.8 | 1.41 | 0.55 |
| 2021 | 1.22 | 2.46 | 0.88 |
| 2020 | 2.08 | 2.79 | 1.54 |
| 2019 | 2.51 | 3 | 1.75 |
| 2018 | 1.76 | 2.33 | 1.29 |
| 2017 | 1.77 | 1.91 | 1.63 |
| 2016 | 2.05 | 5.19 | 1.66 |
| 2015 | 5.82 | 13.01 | 1.92 |
| 2014 | 1.75 | 2.34 | 1.18 |
| 2013 | 2.78 | 3.71 | 2.27 |
| 2012 | 3.01 | 3.82 | 2.24 |
| 2011 | 4.45 | 8.43 | 2.28 |
| 2010 | 10.82 | 20.75 | 7.02 |
| 2009 | 14.28 | 26.14 | 3.65 |
| 2008 | 6.16 | 12.83 | 2.75 |
| 2007 | 11.92 | 19.07 | 3.67 |
| 2006 | 2.56 | 4.19 | 1.44 |
| 2005 | 1.87 | 2.75 | 1.47 |
| 2004 | 3.4 | 5.88 | 1.87 |