| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 10.17 | 11.94 | 8.88 |
| 2024 | 7.47 | 9.89 | 6.71 |
| 2023 | 3.67 | 10.07 | 0.93 |
| 2022 | 9.8 | 11.37 | 6.81 |
| 2021 | 7.8 | 9.95 | 6.28 |
| 2020 | 8.26 | 9.94 | 6.68 |
| 2019 | 9.49 | 10.32 | 8.48 |
| 2018 | 9.26 | 11.08 | 7.97 |
| 2017 | 10.33 | 11.44 | 9.31 |
| 2016 | 8.72 | 11.77 | 6.59 |
| 2015 | 17.59 | 28.42 | 9.42 |
| 2014 | 12.53 | 17.89 | 9.93 |
| 2013 | 13.72 | 20.88 | 9.06 |
| 2012 | 8.53 | 10.36 | 7.1 |
| 2011 | 12.03 | 19.98 | 7.33 |
| 2010 | 12.95 | 16.14 | 10.71 |
| 2009 | 10.46 | 13.68 | 7.09 |
| 2008 | 13.03 | 30.37 | 5.16 |
| 2007 | 28.94 | 37.9 | 20.26 |
| 2006 | 18.83 | 27.01 | 11.92 |
| 2005 | 2.56 | 13.02 | 0.19 |
| 2004 | 0.31 | 0.43 | 0.22 |
| 2003 | 0.36 | 0.42 | 0.3 |
| 2002 | 0.48 | 0.52 | 0.43 |
| 2001 | 0.43 | 0.63 | 0.25 |
| 2000 | 0.2 | 0.27 | 0.14 |
| 1999 | 1.35 | 6.72 | 0.24 |
| 1998 | 0.26 | 0.33 | 0.17 |
| 1997 | 3.16 | 3.9 | 1.88 |