| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.41 | 2.95 | 1.12 |
| 2024 | 1.73 | 2.45 | 0.94 |
| 2023 | 2.26 | 3.3 | 1.61 |
| 2022 | 2.18 | 3.65 | 1.46 |
| 2021 | 2 | 2.55 | 1.52 |
| 2020 | 2.24 | 3.1 | 1.67 |
| 2019 | 3.12 | 4.23 | 2.37 |
| 2018 | 3.31 | 4.48 | 2.14 |
| 2017 | 3.35 | 5.42 | 2.52 |
| 2016 | 4.03 | 5.78 | 2.34 |
| 2015 | 4.12 | 7.6 | 2.17 |
| 2014 | 1.86 | 2.64 | 1.26 |
| 2013 | 2.24 | 3.04 | 1.78 |
| 2012 | 1.92 | 2.6 | 1.33 |
| 2011 | 2.15 | 2.79 | 1.34 |
| 2010 | 3.48 | 7.71 | 1.98 |
| 2009 | 7.78 | 14.78 | 1.69 |
| 2008 | 4.58 | 13.07 | 1.3 |
| 2007 | 7.77 | 17.08 | 1.95 |
| 2006 | 1.49 | 2.49 | 0.56 |
| 2005 | 0.47 | 0.57 | 0.34 |
| 2004 | 0.49 | 0.76 | 0.35 |