| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 16.08 | 50 |
| 2015 | 15.37 | 93 |
| 2014 | 14.74 | 102 |
| 2013 | 13.92 | 123 |
| 2012 | 13.96 | 122 |
| 2011 | 13.59 | 126 |
| 2010 | 12.66 | 126 |
| 2009 | 12.29 | 129 |
| 2008 | 13.49 | 122 |
| 2007 | 13.54 | 125 |
| 2006 | 13.66 | 119 |
| 2005 | 13.27 | 115 |
| 2004 | 13.06 | 109 |
| 2003 | 13.2 | 106 |
| 2002 | 13.92 | 98 |
| 2001 | 14.51 | 92 |
| 2000 | 14.41 | 84 |
| 1999 | 13.36 | 93 |
| 1998 | 12.58 | 99 |
| 1997 | 11.71 | 98 |
| 1996 | 10.86 | 98 |
| 1995 | 10.33 | 101 |
| 1994 | 9.96 | 102 |
| 1993 | 9.42 | 103 |
| 1992 | 8.64 | 101 |
| 1991 | 8.07 | 103 |
| 1990 | 8.22 | 98 |
| 1989 | 9.19 | 84 |
| 1988 | 9.65 | 80 |
| 1987 | 9.76 | 80 |
| 1986 | 9.82 | 78 |