| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 5.85 | 8.67 | 3 |
| 2024 | 4.25 | 5.96 | 2.7 |
| 2023 | 6.3 | 8.12 | 5.27 |
| 2022 | 6.3 | 8.02 | 4.97 |
| 2021 | 6.17 | 8.41 | 4.61 |
| 2020 | 5.99 | 9.8 | 4.39 |
| 2019 | 2.81 | 5.36 | 2.06 |
| 2018 | 3.09 | 3.93 | 2.25 |
| 2017 | 3.58 | 4.55 | 2.89 |
| 2016 | 2.94 | 5.16 | 1.73 |
| 2015 | 3.09 | 4.93 | 1.41 |
| 2014 | 1.24 | 1.72 | 0.93 |
| 2013 | 1.14 | 1.52 | 0.93 |
| 2012 | 1.44 | 2.01 | 1.16 |
| 2011 | 2 | 2.61 | 1.24 |
| 2010 | 4.62 | 5.26 | 3.98 |
| 2009 | 2.89 | 4.87 | 1.03 |
| 2008 | 2.29 | 4.09 | 0.78 |
| 2007 | 2.42 | 3.84 | 1.04 |
| 2006 | 0.92 | 1.11 | 0.71 |
| 2005 | 0.89 | 1.06 | 0.7 |
| 2004 | 1.28 | 1.62 | 1.01 |
| 2003 | 1.52 | 2.51 | 1.24 |
| 2002 | 2.56 | 3.02 | 1.77 |
| 2001 | 3.66 | 4.91 | 2.7 |
| 2000 | 2.88 | 3.72 | 2.16 |
| 1999 | 2.51 | 3.4 | 2.11 |
| 1998 | 2.58 | 3.25 | 1.91 |