| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 0.31 | 0.33 | 0.29 |
| 2025 | 0.31 | 0.35 | 0.25 |
| 2024 | 0.25 | 0.29 | 0.22 |
| 2023 | 0.13 | 0.35 | 0.04 |
| 2022 | 0.35 | 0.4 | 0.32 |
| 2021 | 0.38 | 0.44 | 0.35 |
| 2020 | 0.41 | 0.56 | 0.31 |
| 2019 | 0.59 | 0.68 | 0.5 |
| 2018 | 0.65 | 0.77 | 0.55 |
| 2017 | 0.66 | 0.78 | 0.58 |
| 2016 | 0.6 | 0.69 | 0.57 |
| 2015 | 0.69 | 0.99 | 0.52 |
| 2014 | 0.5 | 0.65 | 0.43 |
| 2013 | 0.56 | 0.68 | 0.51 |
| 2012 | 0.55 | 0.72 | 0.41 |
| 2011 | 0.91 | 1.18 | 0.64 |
| 2010 | 0.74 | 1.1 | 0.49 |
| 2009 | 0.82 | 1.07 | 0.63 |
| 2008 | 1.49 | 3.86 | 0.57 |
| 2007 | 2.85 | 4.67 | 1.99 |
| 2006 | 1.71 | 2.24 | 0.96 |
| 2005 | 0.2 | 1.05 | 0.02 |
| 2004 | 0.03 | 0.05 | 0.01 |