| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 0.89 | 1.07 | 0.68 |
| 2023 | 0.82 | 0.97 | 0.69 |
| 2022 | 1.02 | 1.43 | 0.81 |
| 2021 | 1.25 | 1.74 | 0.98 |
| 2020 | 0.71 | 0.98 | 0.61 |
| 2019 | 0.75 | 1.04 | 0.64 |
| 2018 | 0.85 | 1.08 | 0.72 |
| 2017 | 1.12 | 1.38 | 0.91 |
| 2016 | 0.91 | 1.31 | 0.66 |
| 2015 | 1.13 | 2.06 | 0.72 |
| 2014 | 0.65 | 1.01 | 0.53 |
| 2013 | 0.67 | 0.9 | 0.52 |
| 2012 | 0.86 | 1.01 | 0.74 |
| 2011 | 1.18 | 1.53 | 0.79 |
| 2010 | 1.45 | 2.14 | 1.03 |
| 2009 | 1.7 | 2.46 | 1.02 |
| 2008 | 2.27 | 5.75 | 0.75 |
| 2007 | 6.19 | 13.89 | 1.88 |
| 2006 | 1.47 | 2.11 | 0.7 |
| 2005 | 0.92 | 1.12 | 0.79 |
| 2004 | 1.39 | 1.85 | 1.09 |
| 2003 | 1.64 | 2 | 1.37 |
| 2002 | 2.56 | 3.05 | 2.09 |
| 2001 | 3.28 | 3.78 | 2.51 |
| 2000 | 3.25 | 3.85 | 2.67 |