| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.77 | 0.84 | 0.71 |
| 2024 | 0.81 | 0.96 | 0.66 |
| 2023 | 0.76 | 0.89 | 0.63 |
| 2022 | 0.93 | 1.25 | 0.66 |
| 2021 | 1.51 | 2.08 | 0.96 |
| 2020 | 0.84 | 1.21 | 0.59 |
| 2019 | 0.8 | 1.42 | 0.66 |
| 2018 | 1.45 | 2.55 | 0.7 |
| 2017 | 1.01 | 1.78 | 0.71 |
| 2016 | 0.62 | 0.81 | 0.5 |
| 2015 | 0.8 | 1.5 | 0.56 |
| 2014 | 0.53 | 0.68 | 0.44 |
| 2013 | 0.62 | 0.76 | 0.5 |
| 2012 | 0.71 | 0.94 | 0.47 |
| 2011 | 1.1 | 1.71 | 0.77 |
| 2010 | 0.95 | 1.17 | 0.74 |
| 2009 | 0.79 | 1.19 | 0.53 |
| 2008 | 1.17 | 2.43 | 0.44 |
| 2007 | 1.62 | 2.64 | 0.79 |
| 2006 | 0.75 | 1.12 | 0.46 |
| 2005 | 0.5 | 0.7 | 0.36 |
| 2004 | 0.62 | 1.08 | 0.41 |