| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 16.33 | 2 |
| 2015 | 16.18 | 3 |
| 2014 | 16.04 | 3 |
| 2013 | 15.95 | 4 |
| 2012 | 15.9 | 4 |
| 2011 | 15.82 | 4 |
| 2010 | 15.58 | 2 |
| 2009 | 16.28 | 2 |
| 2008 | 17.14 | 2 |
| 2007 | 18.4 | 2 |
| 2006 | 20.27 | 4 |
| 2005 | 22.83 | 17 |
| 2004 | 24.22 | 21 |
| 2003 | 26.13 | 24 |
| 2002 | 28.64 | 37 |
| 2001 | 31.82 | 45 |
| 2000 | 35.63 | 56 |
| 1999 | 35.85 | 54 |
| 1998 | 36.09 | 51 |
| 1997 | 36.58 | 51 |
| 1996 | 37.33 | 51 |
| 1995 | 38.02 | 52 |
| 1994 | 39.41 | 54 |
| 1993 | 40.9 | 57 |
| 1992 | 42.42 | 60 |
| 1991 | 43.98 | 62 |
| 1990 | 45.57 | 63 |
| 1989 | 46.59 | 61 |
| 1988 | 47.36 | 61 |
| 1987 | 47.86 | 61 |
| 1986 | 48.02 | 59 |