| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.56 | 1.75 | 1.44 |
| 2024 | 1.47 | 1.7 | 1.19 |
| 2023 | 1.44 | 2.22 | 1.06 |
| 2022 | 1.05 | 1.19 | 0.88 |
| 2021 | 0.96 | 1.06 | 0.85 |
| 2020 | 0.91 | 1.06 | 0.74 |
| 2019 | 0.81 | 0.94 | 0.64 |
| 2018 | 0.7 | 0.87 | 0.58 |
| 2017 | 0.71 | 0.89 | 0.58 |
| 2016 | 0.93 | 1.79 | 0.59 |
| 2015 | 2.72 | 5.32 | 1.73 |
| 2014 | 2.44 | 3 | 2.15 |
| 2013 | 2.03 | 3.07 | 1.29 |
| 2012 | 9.55 | 68.53 | 1.09 |
| 2011 | 14.42 | 41.08 | 6.54 |
| 2010 | 6.33 | 7.86 | 4.94 |
| 2009 | 3.51 | 6.07 | 1.34 |
| 2008 | 1.66 | 2.75 | 0.96 |
| 2007 | 0.83 | 1.44 | 0.41 |
| 2006 | 0.38 | 0.5 | 0.24 |
| 2005 | 0.28 | 0.35 | 0.2 |
| 2004 | 0.56 | 1.14 | 0.31 |