| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.89 | 3.2 | 2.52 |
| 2024 | 2.36 | 3.92 | 1.6 |
| 2023 | 2.04 | 2.29 | 1.8 |
| 2022 | 1.91 | 2.09 | 1.73 |
| 2021 | 1.89 | 2.61 | 1.2 |
| 2020 | 1.17 | 2.39 | 0.78 |
| 2019 | 1.06 | 1.38 | 0.91 |
| 2018 | 1.17 | 1.52 | 0.93 |
| 2017 | 1.71 | 2.01 | 1.36 |
| 2016 | 1.94 | 2.23 | 1.49 |
| 2015 | 3.35 | 5.51 | 2.03 |
| 2014 | 3.88 | 4.93 | 3.16 |
| 2013 | 3.14 | 4.63 | 2.46 |
| 2012 | 2.9 | 3.8 | 2.17 |
| 2011 | 5.5 | 8.11 | 2.83 |
| 2010 | 8.52 | 12.98 | 5.55 |
| 2009 | 7.23 | 11.33 | 4.26 |
| 2008 | 4.48 | 6.23 | 2.53 |
| 2007 | 4.24 | 6.32 | 2.06 |
| 2006 | 2.01 | 2.35 | 1.61 |
| 2005 | 1.93 | 2.53 | 1.56 |