| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 6.2 | 97 |
| 2015 | 6.02 | 97 |
| 2014 | 5.86 | 98 |
| 2013 | 5.71 | 98 |
| 2012 | 5.57 | 99 |
| 2011 | 5.45 | 100 |
| 2010 | 5.34 | 101 |
| 2009 | 5.22 | 101 |
| 2008 | 5.12 | 102 |
| 2007 | 5.03 | 103 |
| 2006 | 4.93 | 104 |
| 2005 | 4.83 | 107 |
| 2004 | 4.75 | 109 |
| 2003 | 4.66 | 107 |
| 2002 | 4.57 | 107 |
| 2001 | 4.5 | 107 |
| 2000 | 4.44 | 107 |
| 1999 | 4.4 | 107 |
| 1998 | 4.38 | 107 |
| 1997 | 4.37 | 106 |
| 1996 | 4.36 | 105 |
| 1995 | 4.33 | 105 |
| 1994 | 4.3 | 104 |
| 1993 | 4.26 | 104 |
| 1992 | 4.2 | 104 |
| 1991 | 4.15 | 101 |
| 1990 | 4.09 | 103 |
| 1989 | 4.06 | 102 |
| 1988 | 4.03 | 103 |
| 1987 | 4 | 103 |
| 1986 | 3.98 | 102 |