| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.63 | 0.75 | 0.55 |
| 2024 | 0.44 | 0.78 | 0.2 |
| 2023 | 3.02 | 9.03 | 0.26 |
| 2022 | 4.21 | 9.07 | 2.88 |
| 2021 | 2.81 | 4.51 | 2.33 |
| 2020 | 3.51 | 5.5 | 3.01 |
| 2019 | 3.66 | 5.61 | 2.37 |
| 2018 | 3.37 | 4.57 | 2.24 |
| 2017 | 5.71 | 7.87 | 4.45 |
| 2016 | 5.8 | 7.63 | 3.57 |
| 2015 | 5.97 | 6.93 | 5.16 |
| 2014 | 3.79 | 5.62 | 2.12 |
| 2013 | 2.27 | 2.99 | 1.7 |
| 2012 | 2.91 | 3.99 | 2.19 |
| 2011 | 4.4 | 5.73 | 2.66 |
| 2010 | 4.7 | 6.35 | 3.42 |
| 2009 | 3.59 | 5.79 | 1.95 |
| 2008 | 2.89 | 5.38 | 1.26 |
| 2007 | 4.55 | 8.84 | 1.66 |
| 2006 | 1.85 | 2.19 | 1.51 |
| 2005 | 2.75 | 4.74 | 1.81 |
| 2004 | 3.17 | 5.42 | 2.13 |