| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.2 | 3.67 | 2.76 |
| 2024 | 2.65 | 5.05 | 2.05 |
| 2023 | 2.62 | 3.36 | 2.02 |
| 2022 | 1.33 | 3.19 | 0.81 |
| 2021 | 0.74 | 1.12 | 0.57 |
| 2020 | 0.86 | 1.22 | 0.68 |
| 2019 | 0.76 | 0.95 | 0.54 |
| 2018 | 0.98 | 2.05 | 0.62 |
| 2017 | 4.98 | 7.02 | 1.82 |
| 2016 | 17.19 | 38.68 | 7.02 |
| 2015 | 32.52 | 60.3 | 5.8 |
| 2014 | 3.5 | 4.67 | 2.44 |
| 2013 | 2.26 | 3.38 | 1.56 |
| 2012 | 2.36 | 3.55 | 1.49 |
| 2011 | 4 | 5.21 | 2.56 |
| 2010 | 3.72 | 4.65 | 2.71 |
| 2009 | 3.2 | 4.89 | 1.3 |
| 2008 | 2.08 | 3.69 | 1.04 |
| 2007 | 3.07 | 5.14 | 1.23 |
| 2006 | 1.37 | 1.68 | 1.14 |
| 2005 | 1.95 | 3.02 | 1.45 |
| 2004 | 2.19 | 3.62 | 1.43 |