| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 5.81 | 103 |
| 2015 | 5.64 | 103 |
| 2014 | 5.5 | 103 |
| 2013 | 5.39 | 103 |
| 2012 | 5.3 | 101 |
| 2011 | 5.21 | 102 |
| 2010 | 5.11 | 102 |
| 2009 | 5.05 | 103 |
| 2008 | 4.98 | 104 |
| 2007 | 4.92 | 106 |
| 2006 | 4.85 | 107 |
| 2005 | 4.77 | 110 |
| 2004 | 4.71 | 110 |
| 2003 | 4.64 | 110 |
| 2002 | 4.56 | 109 |
| 2001 | 4.48 | 108 |
| 2000 | 4.4 | 108 |
| 1999 | 4.34 | 108 |
| 1998 | 4.27 | 108 |
| 1997 | 4.21 | 109 |
| 1996 | 4.14 | 110 |
| 1995 | 4.06 | 110 |
| 1994 | 4.02 | 110 |
| 1993 | 3.98 | 113 |
| 1992 | 3.94 | 113 |
| 1991 | 3.88 | 114 |
| 1990 | 3.83 | 115 |
| 1989 | 3.82 | 114 |
| 1988 | 3.8 | 112 |
| 1987 | 3.78 | 113 |
| 1986 | 3.76 | 114 |