| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 0 | ||
| 2025 | 0 | ||
| 2024 | 3.66 | 6.86 | 1.65 |
| 2023 | 5.01 | 6.58 | 3.64 |
| 2022 | 5.49 | 8.42 | 4.05 |
| 2021 | 3.86 | 7.83 | 2.37 |
| 2020 | 3.01 | 4.15 | 1.88 |
| 2019 | 2.37 | 3.09 | 1.84 |
| 2018 | 2.41 | 3.49 | 1.89 |
| 2017 | 4.53 | 5.93 | 3.17 |
| 2016 | 6.76 | 9.33 | 5.85 |
| 2015 | 9.68 | 18.04 | 4.34 |
| 2014 | 3.21 | 6 | 2.02 |
| 2013 | 2.61 | 3.44 | 2.05 |
| 2012 | 4.04 | 5.63 | 2.77 |
| 2011 | 6.27 | 9.95 | 3.85 |
| 2010 | 7.39 | 9.52 | 5.17 |
| 2009 | 5.62 | 7.34 | 4.12 |
| 2008 | 4.2 | 7.15 | 1.45 |
| 2007 | 3.61 | 5.47 | 1.77 |
| 2006 | 2.04 | 2.77 | 1.66 |
| 2005 | 1.7 | 2.57 | 1.28 |
| 2004 | 2.21 | 4.06 | 1.44 |