| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.88 | 1.4 | 0.56 |
| 2024 | 0.43 | 1.17 | 0.28 |
| 2023 | 0.42 | 0.55 | 0.37 |
| 2022 | 0.45 | 0.58 | 0.37 |
| 2021 | 0.64 | 0.87 | 0.51 |
| 2020 | 0.64 | 0.77 | 0.53 |
| 2019 | 0.66 | 0.85 | 0.58 |
| 2018 | 0.85 | 1.03 | 0.6 |
| 2017 | 1.33 | 1.97 | 0.96 |
| 2016 | 1.78 | 2.22 | 1.52 |
| 2015 | 1.36 | 2.46 | 0.87 |
| 2014 | 0.78 | 0.9 | 0.63 |
| 2013 | 0.69 | 0.85 | 0.54 |
| 2012 | 0.61 | 0.79 | 0.48 |
| 2011 | 0.82 | 1.26 | 0.5 |
| 2010 | 1.03 | 1.55 | 0.75 |
| 2009 | 0.89 | 1.35 | 0.45 |
| 2008 | 0.76 | 1.4 | 0.37 |
| 2007 | 1.15 | 1.65 | 0.7 |
| 2006 | 0.92 | 1.24 | 0.7 |
| 2005 | 0.59 | 1.13 | 0.32 |
| 2004 | 0.5 | 0.68 | 0.36 |