| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.64 | 2.94 | 2.34 |
| 2024 | 1.81 | 3.5 | 0.87 |
| 2023 | 1.36 | 2.01 | 0.7 |
| 2022 | 0.84 | 1 | 0.7 |
| 2021 | 0.94 | 1.18 | 0.79 |
| 2020 | 1.26 | 1.86 | 0.97 |
| 2019 | 1.27 | 1.69 | 1.08 |
| 2018 | 1.82 | 2.97 | 1.19 |
| 2017 | 3.06 | 4.21 | 2.31 |
| 2016 | 2.61 | 3.33 | 2.28 |
| 2015 | 4.17 | 7.49 | 2.51 |
| 2014 | 2.31 | 2.99 | 1.88 |
| 2013 | 2.48 | 3.37 | 1.96 |
| 2012 | 3.67 | 4.84 | 2.39 |
| 2011 | 6.65 | 10.34 | 3.34 |
| 2010 | 7.19 | 12.16 | 4.58 |
| 2009 | 5.94 | 9.94 | 2.24 |
| 2008 | 4.35 | 9.53 | 1.6 |
| 2007 | 6.4 | 12.05 | 3.59 |
| 2006 | 2.47 | 4.05 | 1.53 |
| 2005 | 1.73 | 2.53 | 1.26 |
| 2004 | 1.85 | 2.65 | 1.26 |