| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 0.2 | 0.34 | 0.12 |
| 2023 | 0.29 | 0.46 | 0.16 |
| 2022 | 0.53 | 0.7 | 0.33 |
| 2021 | 0.67 | 0.98 | 0.44 |
| 2020 | 1.06 | 1.32 | 0.88 |
| 2019 | 1.01 | 1.33 | 0.84 |
| 2018 | 1.09 | 1.55 | 0.82 |
| 2017 | 1.06 | 1.4 | 0.87 |
| 2016 | 1.35 | 1.69 | 1.1 |
| 2015 | 1.26 | 1.68 | 0.85 |
| 2014 | 1.04 | 1.62 | 0.66 |
| 2013 | 0.89 | 1.26 | 0.65 |
| 2012 | 1.22 | 1.84 | 0.77 |
| 2011 | 1.67 | 2.09 | 1.23 |
| 2010 | 2.03 | 3.22 | 1.4 |
| 2009 | 2.83 | 4.25 | 1.35 |
| 2008 | 2.82 | 7.91 | 0.93 |
| 2007 | 6.98 | 12.22 | 2.58 |
| 2006 | 2.44 | 5.06 | 1.16 |
| 2005 | 1.07 | 1.63 | 0.44 |
| 2004 | 1.5 | 2.46 | 0.89 |