| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.58 | 2.21 | 1.18 |
| 2024 | 1.35 | 1.83 | 0.91 |
| 2023 | 2.04 | 2.47 | 1.63 |
| 2022 | 2.22 | 3.25 | 1.76 |
| 2021 | 5.34 | 7.53 | 2.98 |
| 2020 | 4.65 | 6.2 | 3.46 |
| 2019 | 4.58 | 5.64 | 3.86 |
| 2018 | 4.75 | 6.35 | 3.75 |
| 2017 | 5.81 | 7.38 | 4.64 |
| 2016 | 5.89 | 8.94 | 4.35 |
| 2015 | 6.35 | 10.18 | 3.9 |
| 2014 | 3.35 | 5.62 | 2.59 |
| 2013 | 3.43 | 4.46 | 2.69 |
| 2012 | 2.47 | 3.29 | 1.8 |
| 2011 | 3.04 | 3.73 | 1.94 |
| 2010 | 3.06 | 4.11 | 2.12 |
| 2009 | 2.4 | 3.77 | 1.2 |
| 2008 | 2.07 | 4.16 | 0.92 |
| 2007 | 3.03 | 4.23 | 1.61 |
| 2006 | 1.74 | 2.18 | 1.34 |
| 2005 | 1.27 | 1.47 | 1.04 |
| 2004 | 1.62 | 2.7 | 1.05 |
| 2003 | 2.54 | 3.93 | 1.6 |
| 2002 | 3.88 | 4.68 | 2.87 |
| 2001 | 4.23 | 5.25 | 3.18 |
| 2000 | 4.09 | 5.02 | 2.77 |
| 1999 | 3.43 | 4.17 | 2.74 |
| 1998 | 4.65 | 6.08 | 3.92 |
| 1997 | 5.06 | 7.12 | 3.79 |