| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.79 | 0.92 | 0.67 |
| 2024 | 0.6 | 0.85 | 0.49 |
| 2023 | 0.62 | 0.7 | 0.52 |
| 2022 | 0.6 | 0.93 | 0.49 |
| 2021 | 0.94 | 1.22 | 0.72 |
| 2020 | 1.24 | 1.89 | 0.79 |
| 2019 | 0.89 | 1.24 | 0.73 |
| 2018 | 1.28 | 2.05 | 0.73 |
| 2017 | 1.8 | 2.11 | 1.49 |
| 2016 | 1.2 | 1.74 | 0.71 |
| 2015 | 0.96 | 1.67 | 0.45 |
| 2014 | 0.38 | 0.49 | 0.3 |
| 2013 | 0.33 | 0.36 | 0.29 |
| 2012 | 0.36 | 0.46 | 0.26 |
| 2011 | 0.55 | 0.7 | 0.37 |
| 2010 | 0.77 | 1.17 | 0.54 |
| 2009 | 0.76 | 1.12 | 0.37 |
| 2008 | 0.71 | 1.48 | 0.29 |
| 2007 | 1.59 | 2.18 | 1.01 |
| 2006 | 0.9 | 1.31 | 0.49 |
| 2005 | 0.48 | 0.61 | 0.38 |
| 2004 | 0.77 | 1.24 | 0.45 |