| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.57 | 3.27 | 2.23 |
| 2024 | 2.17 | 4.07 | 1.7 |
| 2023 | 1.98 | 2.18 | 1.72 |
| 2022 | 2.01 | 3.13 | 1.72 |
| 2021 | 1.77 | 2.23 | 1.51 |
| 2020 | 2.01 | 2.64 | 1.54 |
| 2019 | 2.18 | 3.09 | 1.75 |
| 2018 | 2.41 | 2.86 | 1.71 |
| 2017 | 2.65 | 3.38 | 1.97 |
| 2016 | 2.89 | 3.58 | 2.29 |
| 2015 | 2.96 | 5.53 | 1.68 |
| 2014 | 1.61 | 2 | 1.32 |
| 2013 | 2.05 | 2.85 | 1.51 |
| 2012 | 3.02 | 3.68 | 2.39 |
| 2011 | 3.9 | 5.04 | 2.85 |
| 2010 | 4.42 | 5.84 | 3.34 |
| 2009 | 8.49 | 18.16 | 2.41 |
| 2008 | 3.56 | 5.66 | 1.74 |
| 2007 | 4.18 | 6.27 | 2.6 |
| 2006 | 3.72 | 5.46 | 2.55 |
| 2005 | 3.95 | 4.58 | 3.61 |
| 2004 | 4.75 | 6.25 | 3.85 |
| 2003 | 5.7 | 6.65 | 4.96 |
| 2002 | 7.27 | 9.15 | 5.01 |
| 2001 | 13.04 | 19.09 | 8.72 |
| 2000 | 13.12 | 16.28 | 5.72 |
| 1999 | 5.58 | 7.29 | 4.46 |
| 1998 | 5.77 | 9.39 | 4.09 |
| 1997 | 6.39 | 9.48 | 4.84 |