| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 2.39 | 2.82 | 2 |
| 2025 | 1.79 | 2.4 | 1.49 |
| 2024 | 1.66 | 2.33 | 1.29 |
| 2023 | 1.87 | 2.31 | 1.48 |
| 2022 | 1.83 | 2.28 | 1.44 |
| 2021 | 2.45 | 2.92 | 2.11 |
| 2020 | 3.43 | 5.03 | 2.61 |
| 2019 | 2.32 | 2.92 | 1.72 |
| 2018 | 2.45 | 3.22 | 1.73 |
| 2017 | 4.57 | 9.67 | 2.24 |
| 2016 | 6.06 | 9.67 | 3.97 |
| 2015 | 4.93 | 8.68 | 3.68 |
| 2014 | 3.51 | 4.51 | 2.64 |
| 2013 | 2.95 | 4.84 | 2.02 |
| 2012 | 2.93 | 4.74 | 2.17 |
| 2011 | 4.12 | 5.65 | 2.46 |
| 2010 | 4.03 | 4.97 | 2.94 |
| 2009 | 4.07 | 7.29 | 1.85 |
| 2008 | 3.61 | 8.69 | 1.35 |
| 2007 | 5.72 | 8.71 | 2.38 |
| 2006 | 1.98 | 3.49 | 1.35 |
| 2005 | 1.68 | 2.46 | 1.17 |
| 2004 | 2.76 | 3.64 | 2.22 |
| 2003 | 3.25 | 3.75 | 2.8 |
| 2002 | 3.62 | 4.74 | 2.07 |
| 2001 | 3.23 | 4.11 | 2.3 |
| 2000 | 2.82 | 3.59 | 2.07 |
| 1999 | 1.85 | 2.66 | 1.65 |
| 1998 | 3.23 | 3.93 | 2.52 |
| 1997 | 3.34 | 4.83 | 2.64 |