| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 4.04 | 5.53 | 3.66 |
| 2024 | 3.08 | 5.49 | 2.41 |
| 2023 | 2.74 | 3.03 | 2.49 |
| 2022 | 2.57 | 2.85 | 2.29 |
| 2021 | 2.26 | 2.65 | 1.9 |
| 2020 | 2.09 | 2.41 | 1.8 |
| 2019 | 2.49 | 3.46 | 1.83 |
| 2018 | 2.29 | 2.85 | 1.83 |
| 2017 | 3.62 | 4.93 | 2.68 |
| 2016 | 2.69 | 4.02 | 1.21 |
| 2015 | 1.66 | 2.57 | 1.03 |
| 2014 | 0.82 | 1.75 | 0.47 |
| 2013 | 0.65 | 0.92 | 0.5 |
| 2012 | 1.39 | 2.79 | 0.66 |
| 2011 | 7.42 | 12.87 | 2.27 |
| 2010 | 16.39 | 25.84 | 11.47 |
| 2009 | 15.62 | 21.17 | 8.79 |
| 2008 | 13.59 | 31.12 | 5.81 |
| 2007 | 19.09 | 30.61 | 10.31 |
| 2006 | 10.72 | 15.03 | 9.16 |
| 2005 | 8.41 | 10.66 | 5.6 |
| 2004 | 10.57 | 19.06 | 6.23 |