| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.7 | 0.78 | 0.62 |
| 2024 | 0.62 | 0.81 | 0.47 |
| 2023 | 0.99 | 1.47 | 0.71 |
| 2022 | 1.05 | 1.52 | 0.8 |
| 2021 | 0.99 | 1.3 | 0.75 |
| 2020 | 1.32 | 1.87 | 0.94 |
| 2019 | 1.12 | 1.66 | 0.81 |
| 2018 | 2.02 | 3.19 | 1.15 |
| 2017 | 3.23 | 4.2 | 2.47 |
| 2016 | 2.35 | 3.13 | 1.81 |
| 2015 | 1.76 | 3.3 | 0.71 |
| 2014 | 0.68 | 0.86 | 0.48 |
| 2013 | 0.58 | 0.71 | 0.48 |
| 2012 | 0.67 | 0.8 | 0.55 |
| 2011 | 0.95 | 1.27 | 0.63 |
| 2010 | 0.98 | 1.23 | 0.78 |
| 2009 | 0.72 | 1.17 | 0.5 |
| 2008 | 0.76 | 1.68 | 0.37 |
| 2007 | 1.9 | 3.72 | 0.49 |
| 2006 | 0.54 | 0.67 | 0.44 |
| 2005 | 0.64 | 0.94 | 0.46 |
| 2004 | 0.91 | 1.75 | 0.49 |