| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.06 | 1.26 | 0.9 |
| 2024 | 0.99 | 1.26 | 0.63 |
| 2023 | 0.75 | 0.85 | 0.65 |
| 2022 | 0.76 | 1 | 0.58 |
| 2021 | 0.73 | 0.92 | 0.61 |
| 2020 | 0.71 | 0.86 | 0.56 |
| 2019 | 0.63 | 0.86 | 0.52 |
| 2018 | 0.72 | 1.08 | 0.51 |
| 2017 | 1.54 | 2.38 | 0.95 |
| 2016 | 1.7 | 2.16 | 1.38 |
| 2015 | 1.62 | 2.58 | 0.98 |
| 2014 | 0.47 | 1.2 | 0.33 |
| 2013 | 0.44 | 0.59 | 0.35 |
| 2012 | 0.5 | 0.67 | 0.4 |
| 2011 | 0.91 | 1.58 | 0.43 |
| 2010 | 1.17 | 1.67 | 0.91 |
| 2009 | 1.34 | 1.58 | 0.92 |
| 2008 | 1.78 | 3.4 | 0.65 |
| 2007 | 3.04 | 4.6 | 1.66 |
| 2006 | 1.15 | 1.71 | 0.69 |
| 2005 | 0.72 | 0.98 | 0.42 |
| 2004 | 0.84 | 1.33 | 0.48 |