| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.94 | 2.05 | 1.81 |
| 2024 | 1.97 | 2.38 | 1.56 |
| 2023 | 4.12 | 6.21 | 2.16 |
| 2022 | 5.26 | 6.07 | 4.35 |
| 2021 | 5.18 | 6.84 | 4.02 |
| 2020 | 2.61 | 5 | 1.5 |
| 2019 | 1.6 | 2.02 | 1.32 |
| 2018 | 2.12 | 2.85 | 1.4 |
| 2017 | 2.5 | 3.31 | 2.01 |
| 2016 | 4.79 | 8 | 3.1 |
| 2015 | 7.7 | 10.29 | 5.67 |
| 2014 | 4.11 | 6.99 | 3.09 |
| 2013 | 3.51 | 4.26 | 2.96 |
| 2012 | 4.39 | 5.39 | 3.35 |
| 2011 | 5.56 | 7.63 | 4.27 |
| 2010 | 15.08 | 23.26 | 7.4 |
| 2009 | 14.19 | 18.68 | 6.96 |
| 2008 | 9.52 | 15.45 | 5.15 |
| 2007 | 11.86 | 16.28 | 7.31 |
| 2006 | 5.8 | 7.85 | 4.21 |
| 2005 | 3.8 | 5.43 | 2.23 |
| 2004 | 2.77 | 4.39 | 2.2 |