| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 1.08 | 1.34 | 0.87 |
| 2023 | 0.74 | 0.94 | 0.62 |
| 2022 | 0.76 | 1.05 | 0.62 |
| 2021 | 0.73 | 1.56 | 0.53 |
| 2020 | 0.58 | 0.74 | 0.47 |
| 2019 | 0.63 | 0.8 | 0.54 |
| 2018 | 0.79 | 1.11 | 0.62 |
| 2017 | 1.57 | 2.5 | 0.98 |
| 2016 | 1.8 | 2.82 | 1.21 |
| 2015 | 1.34 | 2.11 | 0.97 |
| 2014 | 0.72 | 1.2 | 0.47 |
| 2013 | 0.84 | 1.3 | 0.61 |
| 2012 | 1.05 | 1.39 | 0.73 |
| 2011 | 1.52 | 1.98 | 1 |
| 2010 | 2.04 | 5.17 | 0.93 |
| 2009 | 2.82 | 5.46 | 1.39 |
| 2008 | 4.3 | 7.33 | 1.01 |
| 2007 | 3.36 | 5.69 | 1.37 |
| 2006 | 1.34 | 1.64 | 1.16 |
| 2005 | 1.72 | 2.72 | 1.14 |
| 2004 | 2.57 | 4.34 | 1.68 |