| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.98 | 2.3 | 1.72 |
| 2024 | 1.8 | 2.44 | 1.43 |
| 2023 | 2.45 | 3.21 | 2.02 |
| 2022 | 2.88 | 4.8 | 2.16 |
| 2021 | 2 | 5.87 | 1.44 |
| 2020 | 1.73 | 2.16 | 1.55 |
| 2019 | 2.17 | 2.95 | 1.66 |
| 2018 | 2.6 | 4.14 | 1.55 |
| 2017 | 4.87 | 6.94 | 3.75 |
| 2016 | 5.09 | 6.72 | 3.73 |
| 2015 | 7.74 | 10.9 | 3.56 |
| 2014 | 3.19 | 4.32 | 2.24 |
| 2013 | 2.46 | 2.84 | 2.12 |
| 2012 | 2.85 | 3.68 | 2.22 |
| 2011 | 4.05 | 5.29 | 2.9 |
| 2010 | 4.3 | 5.42 | 3.21 |
| 2009 | 3.5 | 5.32 | 1.94 |
| 2008 | 3.35 | 5.8 | 1.58 |
| 2007 | 4.46 | 6.96 | 1.67 |
| 2006 | 1.99 | 2.84 | 1.57 |
| 2005 | 1.89 | 2.41 | 1.49 |
| 2004 | 2.84 | 5.2 | 2.22 |
| 2003 | 3.82 | 4.65 | 2.9 |
| 2002 | 4.48 | 5.17 | 3.16 |
| 2001 | 6.16 | 7.96 | 4.31 |
| 2000 | 7.11 | 8.12 | 5.45 |
| 1999 | 5.57 | 6.77 | 4.16 |