| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 2.94 | 3.66 | 2.47 |
| 2025 | 2.25 | 3.06 | 2.02 |
| 2024 | 1.91 | 2.92 | 1.44 |
| 2023 | 1.97 | 2.31 | 1.66 |
| 2022 | 1.9 | 2.78 | 1.6 |
| 2021 | 1.82 | 2.13 | 1.53 |
| 2020 | 2.12 | 2.96 | 1.57 |
| 2019 | 2.16 | 2.77 | 1.83 |
| 2018 | 2.49 | 3.32 | 1.89 |
| 2017 | 4.29 | 6.31 | 2.99 |
| 2016 | 4.95 | 6.62 | 3.61 |
| 2015 | 6.77 | 10.76 | 3.82 |
| 2014 | 4.54 | 5.57 | 3.66 |
| 2013 | 3.39 | 5.13 | 2.62 |
| 2012 | 3.18 | 4.16 | 2.57 |
| 2011 | 4.98 | 6.25 | 2.99 |
| 2010 | 7.39 | 10.33 | 5.55 |
| 2009 | 4.58 | 6.93 | 2.78 |
| 2008 | 4.28 | 6.66 | 2.41 |
| 2007 | 5.42 | 8.91 | 2.42 |
| 2006 | 2.34 | 3.07 | 1.67 |
| 2005 | 1.92 | 2.66 | 1.34 |
| 2004 | 3.25 | 4.48 | 2.57 |
| 2003 | 3.57 | 4.41 | 2.84 |
| 2002 | 5.17 | 6.48 | 4.24 |
| 2001 | 6.84 | 8.01 | 5.57 |
| 2000 | 8.66 | 12.35 | 5.71 |
| 1999 | 4.81 | 6.22 | 3.5 |
| 1998 | 4.67 | 6.26 | 2.9 |
| 1997 | 4.02 | 6.01 | 2.27 |