| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 0.96 | 1.18 | 0.76 |
| 2023 | 0.91 | 1.12 | 0.74 |
| 2022 | 1.02 | 1.28 | 0.84 |
| 2021 | 1.26 | 1.55 | 1.01 |
| 2020 | 0.68 | 1.28 | 0.47 |
| 2019 | 0.56 | 0.67 | 0.47 |
| 2018 | 0.65 | 0.91 | 0.45 |
| 2017 | 0.64 | 0.8 | 0.54 |
| 2016 | 0.64 | 0.75 | 0.54 |
| 2015 | 0.81 | 1.11 | 0.6 |
| 2014 | 0.54 | 0.71 | 0.42 |
| 2013 | 0.45 | 0.65 | 0.35 |
| 2012 | 0.39 | 0.46 | 0.32 |
| 2011 | 0.53 | 0.8 | 0.3 |
| 2010 | 0.75 | 1.04 | 0.55 |
| 2009 | 0.65 | 1.07 | 0.36 |
| 2008 | 0.57 | 1.18 | 0.31 |
| 2007 | 0.95 | 1.46 | 0.61 |
| 2006 | 0.36 | 0.62 | 0.28 |
| 2005 | 0.3 | 0.38 | 0.23 |
| 2004 | 0.41 | 0.71 | 0.26 |