| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 0.46 | 0.65 | 0.38 |
| 2025 | 0.34 | 0.53 | 0.26 |
| 2024 | 0.29 | 0.4 | 0.19 |
| 2023 | 0.49 | 0.6 | 0.38 |
| 2022 | 0.61 | 0.75 | 0.52 |
| 2021 | 0.7 | 1.03 | 0.45 |
| 2020 | 3.89 | 13.82 | 0.86 |
| 2019 | 2.18 | 2.78 | 1.89 |
| 2018 | 2.11 | 2.6 | 1.66 |
| 2017 | 3.78 | 6.24 | 2.31 |
| 2016 | 4.88 | 6.71 | 3.06 |
| 2015 | 3.22 | 6.27 | 1.8 |
| 2014 | 1.64 | 2.42 | 0.9 |
| 2013 | 0.94 | 1.05 | 0.78 |
| 2012 | 0.92 | 1.18 | 0.77 |
| 2011 | 1.47 | 2.01 | 0.91 |
| 2010 | 1.83 | 2.63 | 1.34 |
| 2009 | 1.86 | 2.54 | 0.95 |
| 2008 | 1.34 | 2.38 | 0.7 |
| 2007 | 1.86 | 3.03 | 0.84 |
| 2006 | 0.9 | 1.21 | 0.55 |
| 2005 | 0.91 | 1.31 | 0.77 |
| 2004 | 1.15 | 1.8 | 0.83 |