| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.79 | 0.86 | 0.72 |
| 2024 | 0.74 | 0.87 | 0.57 |
| 2023 | 0.72 | 0.89 | 0.6 |
| 2022 | 1.04 | 1.35 | 0.79 |
| 2021 | 1.22 | 2.52 | 0.73 |
| 2020 | 0.62 | 1.2 | 0.51 |
| 2019 | 0.71 | 1.13 | 0.57 |
| 2018 | 1.23 | 1.72 | 0.72 |
| 2017 | 0.98 | 1.34 | 0.7 |
| 2016 | 0.79 | 1.12 | 0.59 |
| 2015 | 1 | 1.79 | 0.57 |
| 2014 | 1 | 1.38 | 0.82 |
| 2013 | 1.32 | 1.78 | 0.85 |
| 2012 | 0.99 | 1.19 | 0.73 |
| 2011 | 1.76 | 2.55 | 0.9 |
| 2010 | 2.61 | 3.8 | 1.61 |
| 2009 | 2.16 | 3.82 | 1.28 |
| 2008 | 3.52 | 7.64 | 1.02 |
| 2007 | 4.05 | 6.25 | 2.03 |
| 2006 | 1.31 | 2.06 | 1 |
| 2005 | 0.98 | 1.29 | 0.72 |
| 2004 | 0.96 | 1.7 | 0.62 |