| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.26 | 0.32 | 0.22 |
| 2024 | 0.35 | 0.5 | 0.25 |
| 2023 | 0.3 | 0.44 | 0.23 |
| 2022 | 0.23 | 0.28 | 0.19 |
| 2021 | 0.23 | 0.43 | 0.18 |
| 2020 | 0.23 | 0.43 | 0.18 |
| 2019 | 0.21 | 0.27 | 0.18 |
| 2018 | 0.24 | 0.35 | 0.16 |
| 2017 | 0.49 | 0.67 | 0.33 |
| 2016 | 0.47 | 0.67 | 0.36 |
| 2015 | 0.53 | 0.82 | 0.39 |
| 2014 | 0.4 | 0.51 | 0.32 |
| 2013 | 0.31 | 0.38 | 0.25 |
| 2012 | 0.33 | 0.42 | 0.27 |
| 2011 | 0.56 | 0.81 | 0.32 |
| 2010 | 0.67 | 1.2 | 0.48 |
| 2009 | 0.62 | 1.17 | 0.3 |
| 2008 | 0.5 | 1.03 | 0.22 |
| 2007 | 1.06 | 1.98 | 0.57 |
| 2006 | 0.6 | 0.78 | 0.5 |
| 2005 | 0.46 | 0.71 | 0.3 |
| 2004 | 0.6 | 0.87 | 0.38 |