| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.54 | 1.66 | 1.38 |
| 2024 | 1.33 | 2.29 | 1.07 |
| 2023 | 1.59 | 1.83 | 1.43 |
| 2022 | 3.64 | 8.84 | 1.5 |
| 2021 | 2.75 | 8.15 | 2.1 |
| 2020 | 2.85 | 3.77 | 2.39 |
| 2019 | 2.86 | 3.57 | 2.34 |
| 2018 | 3.02 | 3.62 | 2.57 |
| 2017 | 4.56 | 6.68 | 3.33 |
| 2016 | 5.28 | 7 | 4 |
| 2015 | 5.9 | 11.14 | 3.73 |
| 2014 | 3.41 | 4.5 | 2.84 |
| 2013 | 3.19 | 3.85 | 2.71 |
| 2012 | 3.55 | 4.46 | 2.64 |
| 2011 | 4.98 | 7.29 | 3.58 |
| 2010 | 4.8 | 5.95 | 3.27 |
| 2009 | 4.09 | 5.82 | 1.87 |
| 2008 | 3.39 | 7.87 | 1.26 |
| 2007 | 4.38 | 7.18 | 2.36 |
| 2006 | 3.06 | 4.17 | 2.18 |
| 2005 | 3.72 | 4.04 | 3.49 |
| 2004 | 3.78 | 4.65 | 2.27 |
| 2003 | 3.81 | 4.39 | 2.68 |
| 2002 | 5.35 | 6.76 | 4.16 |
| 2001 | 8.46 | 10.69 | 6.04 |
| 2000 | 9.34 | 10.96 | 7.06 |
| 1999 | 10.09 | 13.12 | 8.07 |
| 1998 | 7.94 | 11.63 | 5.43 |