| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.38 | 0.56 | 0.27 |
| 2024 | 0.32 | 0.43 | 0.22 |
| 2023 | 0.57 | 0.85 | 0.37 |
| 2022 | 0.5 | 1 | 0.26 |
| 2021 | 6.31 | 13.85 | 0.63 |
| 2020 | 5.82 | 9.58 | 3.43 |
| 2019 | 2.72 | 4.15 | 1.69 |
| 2018 | 1.99 | 2.87 | 1.46 |
| 2017 | 3.2 | 3.79 | 2.23 |
| 2016 | 2.77 | 3.58 | 2.04 |
| 2015 | 1.65 | 3.29 | 0.78 |
| 2014 | 1.33 | 2.01 | 1.05 |
| 2013 | 1.28 | 1.67 | 0.95 |
| 2012 | 0.99 | 1.43 | 0.68 |
| 2011 | 1.18 | 1.62 | 0.72 |
| 2010 | 1.79 | 2.42 | 1.4 |
| 2009 | 1.17 | 2.12 | 0.57 |
| 2008 | 0.92 | 1.69 | 0.39 |
| 2007 | 1.14 | 1.73 | 0.59 |
| 2006 | 0.62 | 0.81 | 0.53 |
| 2005 | 0.68 | 0.83 | 0.43 |
| 2004 | 0.89 | 1.75 | 0.55 |