| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.67 | 1.84 | 1.25 |
| 2024 | 2.47 | 4.94 | 1.23 |
| 2023 | 4.62 | 6.41 | 3.77 |
| 2022 | 5.17 | 6.7 | 4.34 |
| 2021 | 6.52 | 8.47 | 5.04 |
| 2020 | 4.2 | 6.74 | 2.64 |
| 2019 | 0.88 | 3.85 | 0.29 |
| 2018 | 1.46 | 4.85 | 0.4 |
| 2017 | 9.4 | 18.22 | 3.28 |
| 2016 | 18.48 | 24.36 | 12.29 |
| 2015 | 21.1 | 24.9 | 10.88 |
| 2014 | 10.2 | 12.88 | 8.29 |
| 2013 | 9.52 | 12.24 | 6.94 |
| 2012 | 5.96 | 7.8 | 3.86 |
| 2011 | 5.03 | 5.94 | 3.79 |
| 2010 | 4.45 | 5.7 | 3.23 |
| 2009 | 3.36 | 5.71 | 1.46 |
| 2008 | 2.83 | 5.61 | 1.11 |
| 2007 | 3.42 | 4.9 | 1.68 |
| 2006 | 1.09 | 1.68 | 0.61 |
| 2005 | 0.63 | 0.82 | 0.47 |
| 2004 | 0.84 | 1.9 | 0.62 |