| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 0 | ||
| 2025 | 0 | ||
| 2024 | 3.31 | 5.99 | 0.72 |
| 2023 | 5.82 | 7.16 | 4.88 |
| 2022 | 8.23 | 13.36 | 6.18 |
| 2021 | 7.95 | 15.19 | 4.09 |
| 2020 | 4.71 | 5.56 | 3.99 |
| 2019 | 1.94 | 3.14 | 1.41 |
| 2018 | 2.55 | 5.31 | 1.4 |
| 2017 | 5.59 | 9.61 | 3.55 |
| 2016 | 3.41 | 5.43 | 1.98 |
| 2015 | 1.97 | 1.99 | 1.95 |
| 2014 | 2.47 | 5.04 | 1.67 |
| 2013 | 3.5 | 4.16 | 2.86 |
| 2012 | 5.4 | 6.8 | 2.85 |
| 2011 | 6.67 | 10.81 | 4.49 |
| 2010 | 7.68 | 11.5 | 5.3 |
| 2009 | 4.4 | 6.01 | 2.42 |
| 2008 | 7.14 | 23.46 | 1.65 |
| 2007 | 15.61 | 27.06 | 3.18 |
| 2006 | 2.24 | 3.94 | 1.04 |
| 2005 | 1.25 | 2.23 | 0.78 |
| 2004 | 2.59 | 4.31 | 1.92 |
| 2003 | 2.98 | 3.51 | 2.19 |
| 2002 | 4.18 | 4.74 | 3.91 |
| 2001 | 5.14 | 6.19 | 3.8 |