| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.53 | 1.78 | 1.32 |
| 2024 | 1.95 | 2.46 | 1.5 |
| 2023 | 1.98 | 2.54 | 1.58 |
| 2022 | 1.82 | 3.28 | 0.68 |
| 2021 | 0.83 | 1 | 0.69 |
| 2020 | 1.01 | 1.57 | 0.79 |
| 2019 | 0.88 | 1.09 | 0.64 |
| 2018 | 0.73 | 0.94 | 0.59 |
| 2017 | 0.97 | 1.11 | 0.87 |
| 2016 | 1.03 | 1.36 | 0.9 |
| 2015 | 1.71 | 2.63 | 1.2 |
| 2014 | 0.79 | 1.66 | 0.59 |
| 2013 | 0.64 | 0.84 | 0.49 |
| 2012 | 0.77 | 0.98 | 0.61 |
| 2011 | 1.25 | 1.62 | 0.84 |
| 2010 | 1.72 | 2.59 | 1.24 |
| 2009 | 2.1 | 2.92 | 1.37 |
| 2008 | 4.21 | 9.26 | 1.11 |
| 2007 | 5.95 | 10.52 | 2.95 |
| 2006 | 2.1 | 2.94 | 1.71 |
| 2005 | 1.92 | 2.75 | 1.24 |
| 2004 | 2.54 | 3.01 | 2.09 |
| 2003 | 2.06 | 2.8 | 1.74 |