| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 0.62 | 1.08 | 0.44 |
| 2023 | 0.57 | 0.75 | 0.48 |
| 2022 | 0.54 | 0.67 | 0.45 |
| 2021 | 0.74 | 1.02 | 0.57 |
| 2020 | 0.79 | 1.06 | 0.63 |
| 2019 | 0.81 | 0.98 | 0.69 |
| 2018 | 0.96 | 1.38 | 0.66 |
| 2017 | 1.14 | 1.47 | 1.02 |
| 2016 | 1.12 | 1.41 | 1 |
| 2015 | 1.44 | 2.2 | 0.9 |
| 2014 | 0.92 | 1.31 | 0.75 |
| 2013 | 0.63 | 0.97 | 0.36 |
| 2012 | 0.59 | 0.7 | 0.43 |
| 2011 | 0.92 | 1.27 | 0.53 |
| 2010 | 1.02 | 1.38 | 0.82 |
| 2009 | 1.25 | 1.5 | 0.82 |
| 2008 | 1.63 | 3.38 | 0.57 |
| 2007 | 2.6 | 4.18 | 1.17 |
| 2006 | 0.83 | 1.21 | 0.48 |
| 2005 | 0.45 | 0.56 | 0.32 |
| 2004 | 0.66 | 1.23 | 0.36 |