| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0 | ||
| 2024 | 0 | ||
| 2023 | 0 | ||
| 2022 | 0.47 | 0.73 | 0.21 |
| 2021 | 0.62 | 0.94 | 0.32 |
| 2020 | 1.01 | 1.53 | 0.68 |
| 2019 | 0.98 | 1.8 | 0.46 |
| 2018 | 0.78 | 1.37 | 0.44 |
| 2017 | 0.92 | 1.1 | 0.75 |
| 2016 | 3.55 | 9.17 | 1.02 |
| 2015 | 20.26 | 53.31 | 7.18 |
| 2014 | 6.16 | 10.73 | 4.63 |
| 2013 | 4.78 | 5.49 | 3.89 |
| 2012 | 4.33 | 5.5 | 3.43 |
| 2011 | 6.06 | 7.4 | 3.98 |
| 2010 | 7.2 | 10.93 | 5.03 |
| 2009 | 7.9 | 10.13 | 5.45 |
| 2008 | 8.96 | 18.47 | 4.27 |
| 2007 | 8.1 | 13.8 | 2.48 |
| 2006 | 2.02 | 3.04 | 1.23 |
| 2005 | 1.81 | 2.4 | 1.44 |
| 2004 | 3.83 | 7.5 | 2.1 |