| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 5.47 | 6.9 | 4.39 |
| 2024 | 3.88 | 7.36 | 2.4 |
| 2023 | 2.68 | 3.35 | 2.18 |
| 2022 | 2.72 | 3.64 | 1.91 |
| 2021 | 2.62 | 3.69 | 2.02 |
| 2020 | 2.42 | 3.11 | 1.92 |
| 2019 | 2.52 | 3.24 | 1.96 |
| 2018 | 2.29 | 3.16 | 1.78 |
| 2017 | 4.06 | 5.81 | 2.48 |
| 2016 | 5.5 | 7.38 | 4.52 |
| 2015 | 8.12 | 13.95 | 4.55 |
| 2014 | 5.18 | 6.82 | 3.32 |
| 2013 | 3.48 | 4.72 | 2.51 |
| 2012 | 3.39 | 4.3 | 2.2 |
| 2011 | 5.08 | 8.38 | 3.22 |
| 2010 | 8.99 | 16.24 | 3.48 |
| 2009 | 7.97 | 10.83 | 4.93 |
| 2008 | 8.76 | 15.35 | 2.98 |
| 2007 | 10.42 | 16.3 | 7.74 |
| 2006 | 6.77 | 9.97 | 4.77 |
| 2005 | 4.62 | 6.01 | 3.61 |
| 2004 | 6.99 | 10.53 | 3.75 |
| 2003 | 9.06 | 11.11 | 7.34 |
| 2002 | 10.88 | 14.6 | 5.9 |
| 2001 | 14.75 | 22.94 | 8.96 |
| 2000 | 28.5 | 48.03 | 15.03 |
| 1999 | 11.3 | 16.69 | 8.09 |