| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.93 | 2.16 | 1.63 |
| 2024 | 1.35 | 1.89 | 1.09 |
| 2023 | 1.22 | 1.39 | 1.06 |
| 2022 | 0.94 | 1.19 | 0.8 |
| 2021 | 0.95 | 1.07 | 0.88 |
| 2020 | 0.91 | 1.06 | 0.69 |
| 2019 | 2.39 | 6.55 | 0.9 |
| 2018 | 2.52 | 6.45 | 1.95 |
| 2017 | 3.73 | 4.49 | 3 |
| 2016 | 3.69 | 4.45 | 3.24 |
| 2015 | 5.02 | 5.65 | 4.16 |
| 2014 | 3.68 | 4.74 | 3.14 |
| 2013 | 3.78 | 4.4 | 3.16 |
| 2012 | 2.89 | 3.21 | 2.59 |
| 2011 | 3.44 | 5.02 | 2.35 |
| 2010 | 4.54 | 5.13 | 3.74 |
| 2009 | 3.27 | 5.15 | 1.87 |
| 2008 | 3.13 | 5.92 | 1.74 |
| 2007 | 5.92 | 7.36 | 4.67 |
| 2006 | 4.67 | 5.85 | 3.88 |
| 2005 | 1.82 | 4.38 | 0.93 |
| 2004 | 1.15 | 1.81 | 0.86 |