| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 0.9 | 1.24 | 0.68 |
| 2023 | 0.84 | 1.04 | 0.64 |
| 2022 | 0.54 | 0.71 | 0.41 |
| 2021 | 0.68 | 1.04 | 0.49 |
| 2020 | 0.82 | 1.16 | 0.66 |
| 2019 | 0.75 | 0.98 | 0.65 |
| 2018 | 0.82 | 1.02 | 0.64 |
| 2017 | 1.21 | 1.63 | 0.92 |
| 2016 | 1.16 | 1.35 | 0.95 |
| 2015 | 1.43 | 2.21 | 0.99 |
| 2014 | 1.01 | 1.41 | 0.88 |
| 2013 | 0.78 | 1.11 | 0.65 |
| 2012 | 0.74 | 0.88 | 0.62 |
| 2011 | 1.09 | 1.6 | 0.64 |
| 2010 | 1.5 | 2.01 | 1.15 |
| 2009 | 1.25 | 1.84 | 0.68 |
| 2008 | 1.79 | 4.47 | 0.55 |
| 2007 | 3.89 | 5.09 | 3.19 |
| 2006 | 1.98 | 3.28 | 0.99 |
| 2005 | 1.14 | 1.39 | 0.79 |
| 2004 | 1.38 | 2.61 | 0.82 |