| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.74 | 1.91 | 1.48 |
| 2024 | 1.65 | 1.98 | 1.32 |
| 2023 | 2.3 | 3.3 | 1.52 |
| 2022 | 3.78 | 5.83 | 2.36 |
| 2021 | 5.24 | 9.7 | 2.58 |
| 2020 | 1.77 | 3.05 | 1.36 |
| 2019 | 1.67 | 2.07 | 1.48 |
| 2018 | 2.85 | 7.85 | 1.68 |
| 2017 | 1.85 | 2.37 | 1.73 |
| 2016 | 1.74 | 2.26 | 1.53 |
| 2015 | 2.44 | 4.65 | 1.67 |
| 2014 | 1.41 | 2.14 | 1.15 |
| 2013 | 1.37 | 1.54 | 1.14 |
| 2012 | 1.43 | 1.63 | 1.26 |
| 2011 | 1.96 | 2.49 | 1.32 |
| 2010 | 2.77 | 3.58 | 2.17 |
| 2009 | 2.83 | 3.74 | 1.7 |
| 2008 | 3.4 | 7.22 | 1.4 |
| 2007 | 5.33 | 9.55 | 1.94 |
| 2006 | 1.39 | 1.96 | 0.9 |
| 2005 | 0.9 | 1.22 | 0.63 |
| 2004 | 1.6 | 2.06 | 1.2 |
| 2003 | 2.09 | 2.51 | 1.64 |
| 2002 | 2.86 | 3.66 | 2.08 |
| 2001 | 4.66 | 5.43 | 3.24 |