| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 19.83 | 8 |
| 2015 | 19.6 | 8 |
| 2014 | 19.39 | 8 |
| 2013 | 19.12 | 7 |
| 2012 | 18.81 | 7 |
| 2011 | 18.5 | 6 |
| 2010 | 18.22 | 6 |
| 2009 | 17.97 | 7 |
| 2008 | 17.75 | 7 |
| 2007 | 17.55 | 7 |
| 2006 | 17.4 | 8 |
| 2005 | 17.31 | 6 |
| 2004 | 17.22 | 7 |
| 2003 | 17.22 | 5 |
| 2002 | 17.26 | 4 |
| 2001 | 17.3 | 3 |
| 2000 | 17.3 | 2 |
| 1999 | 17.35 | 2 |
| 1998 | 17.39 | 2 |
| 1997 | 17.43 | 1 |
| 1996 | 17.46 | 1 |
| 1995 | 17.51 | 1 |
| 1994 | 17.61 | 1 |
| 1993 | 17.7 | 1 |
| 1992 | 17.78 | 1 |
| 1991 | 17.82 | 1 |
| 1990 | 17.82 | 1 |
| 1989 | 17.79 | 1 |
| 1988 | 17.71 | 1 |
| 1987 | 17.58 | 1 |
| 1986 | 17.43 | 1 |