| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 7.51 | 79 |
| 2015 | 7.56 | 80 |
| 2014 | 7.75 | 86 |
| 2013 | 7.95 | 87 |
| 2012 | 8.16 | 91 |
| 2011 | 8.37 | 93 |
| 2010 | 8.59 | 96 |
| 2009 | 8.84 | 98 |
| 2008 | 9.1 | 101 |
| 2007 | 9.36 | 105 |
| 2006 | 9.63 | 109 |
| 2005 | 9.89 | 112 |
| 2004 | 10.12 | 117 |
| 2003 | 10.35 | 123 |
| 2002 | 10.57 | 125 |
| 2001 | 10.77 | 129 |
| 2000 | 10.94 | 129 |
| 1999 | 11.08 | 131 |
| 1998 | 11.19 | 134 |
| 1997 | 11.28 | 133 |
| 1996 | 11.35 | 132 |
| 1995 | 11.38 | 133 |
| 1994 | 11.43 | 134 |
| 1993 | 11.46 | 134 |
| 1992 | 11.46 | 135 |
| 1991 | 11.45 | 137 |
| 1990 | 11.42 | 137 |
| 1989 | 11.44 | 138 |
| 1988 | 11.45 | 138 |
| 1987 | 11.46 | 140 |
| 1986 | 11.44 | 140 |