| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.8 | 1 | 0.7 |
| 2024 | 0.72 | 0.92 | 0.43 |
| 2023 | 0.6 | 0.71 | 0.5 |
| 2022 | 0.83 | 1.17 | 0.62 |
| 2021 | 0.6 | 1.79 | 0.18 |
| 2020 | 0.18 | 0.22 | 0.16 |
| 2019 | 0.22 | 0.37 | 0.17 |
| 2018 | 0.22 | 0.35 | 0.16 |
| 2017 | 0.38 | 0.46 | 0.31 |
| 2016 | 0.33 | 0.42 | 0.28 |
| 2015 | 0.39 | 0.62 | 0.31 |
| 2014 | 0.26 | 0.36 | 0.22 |
| 2013 | 0.4 | 0.59 | 0.28 |
| 2012 | 0.61 | 0.83 | 0.42 |
| 2011 | 0.86 | 1.1 | 0.57 |
| 2010 | 1.13 | 1.7 | 0.76 |
| 2009 | 1.06 | 1.46 | 0.63 |
| 2008 | 1.81 | 3.9 | 0.47 |
| 2007 | 2.11 | 3.33 | 0.99 |
| 2006 | 0.94 | 1.3 | 0.65 |
| 2005 | 0.81 | 1.17 | 0.6 |
| 2004 | 1.18 | 1.81 | 0.74 |