| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0 | ||
| 2024 | 0 | ||
| 2023 | 0.62 | 0.96 | 0.28 |
| 2022 | 0.89 | 1.24 | 0.56 |
| 2021 | 0.71 | 0.92 | 0.48 |
| 2020 | 1.05 | 1.7 | 0.67 |
| 2019 | 1.42 | 2.59 | 0.78 |
| 2018 | 2.24 | 2.41 | 2 |
| 2017 | 1.76 | 2.09 | 1.44 |
| 2016 | 1.92 | 2.56 | 1.66 |
| 2015 | 3.43 | 5.92 | 1.74 |
| 2014 | 0.97 | 1.93 | 0.71 |
| 2013 | 1.97 | 2.67 | 1.08 |
| 2012 | 2.57 | 3.34 | 1.98 |
| 2011 | 4.39 | 8.49 | 2.01 |
| 2010 | 5.63 | 7.15 | 3.61 |
| 2009 | 6.43 | 10.61 | 3.1 |
| 2008 | 4.63 | 8.54 | 2.26 |
| 2007 | 10.11 | 17.76 | 3.78 |
| 2006 | 3.04 | 4.55 | 1.8 |
| 2005 | 2.22 | 3.06 | 1.54 |
| 2004 | 4.87 | 8.69 | 2.82 |