| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.59 | 4.86 | 1.98 |
| 2024 | 2.69 | 5.43 | 1.38 |
| 2023 | 3.53 | 5 | 2.48 |
| 2022 | 2.75 | 4.33 | 1.64 |
| 2021 | 2.17 | 2.93 | 1.61 |
| 2020 | 2.36 | 3.05 | 1.67 |
| 2019 | 2.57 | 3.65 | 2.05 |
| 2018 | 4.32 | 5.98 | 2.21 |
| 2017 | 5.03 | 6.14 | 3.86 |
| 2016 | 3.52 | 4.31 | 2.7 |
| 2015 | 4.12 | 10.94 | 2.16 |
| 2014 | 1.98 | 2.53 | 1.38 |
| 2013 | 2.18 | 3.06 | 1.72 |
| 2012 | 1.51 | 1.83 | 1.17 |
| 2011 | 1.9 | 2.58 | 1.26 |
| 2010 | 2.57 | 3.59 | 1.69 |
| 2009 | 2.04 | 3.22 | 1.01 |
| 2008 | 4.45 | 13.29 | 0.84 |
| 2007 | 10.67 | 17.44 | 2.7 |
| 2006 | 2.83 | 3.36 | 2.16 |
| 2005 | 3.45 | 4.31 | 2.95 |
| 2004 | 5.39 | 7.87 | 3.83 |
| 2003 | 8.71 | 11.57 | 6.32 |
| 2002 | 10.66 | 11.56 | 9.52 |
| 2001 | 10.75 | 12.87 | 9.02 |
| 2000 | 8.62 | 11.99 | 4.35 |
| 1999 | 2.51 | 2.96 | 1.99 |
| 1998 | 2.89 | 3.92 | 1.92 |
| 1997 | 2.05 | 2.73 | 1.36 |