| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.17 | 1.26 | 1.12 |
| 2024 | 1.02 | 1.19 | 0.83 |
| 2023 | 0.79 | 0.94 | 0.68 |
| 2022 | 0.71 | 0.87 | 0.63 |
| 2021 | 0.91 | 1.05 | 0.74 |
| 2020 | 0.9 | 1.15 | 0.69 |
| 2019 | 0.81 | 0.92 | 0.72 |
| 2018 | 0.86 | 1.18 | 0.7 |
| 2017 | 1.21 | 1.42 | 1.07 |
| 2016 | 1.2 | 1.42 | 1.05 |
| 2015 | 1.56 | 2.59 | 1.06 |
| 2014 | 0.8 | 1.21 | 0.69 |
| 2013 | 0.84 | 1.01 | 0.74 |
| 2012 | 0.99 | 1.21 | 0.83 |
| 2011 | 1.51 | 1.98 | 0.96 |
| 2010 | 1.85 | 2.29 | 1.56 |
| 2009 | 1.98 | 2.3 | 1.76 |
| 2008 | 2.6 | 4.41 | 1.8 |
| 2007 | 3.55 | 4.89 | 2.11 |
| 2006 | 1.75 | 2.05 | 1.4 |
| 2005 | 2.09 | 2.4 | 1.76 |
| 2004 | 2.33 | 3.05 | 1.89 |
| 2003 | 2.59 | 2.87 | 2.37 |