| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 17.61 | 1 |
| 2015 | 17.38 | 1 |
| 2014 | 17.2 | 1 |
| 2013 | 17.04 | 2 |
| 2012 | 16.92 | 2 |
| 2011 | 16.77 | 2 |
| 2010 | 16.45 | 1 |
| 2009 | 17.16 | 1 |
| 2008 | 18.05 | 1 |
| 2007 | 19.34 | 1 |
| 2006 | 21.3 | 1 |
| 2005 | 23.97 | 1 |
| 2004 | 25.4 | 1 |
| 2003 | 27.36 | 1 |
| 2002 | 29.94 | 1 |
| 2001 | 33.22 | 1 |
| 2000 | 37.13 | 1 |
| 1999 | 37.36 | 1 |
| 1998 | 37.59 | 1 |
| 1997 | 38.05 | 1 |
| 1996 | 38.78 | 1 |
| 1995 | 39.49 | 1 |
| 1994 | 40.93 | 4 |
| 1993 | 42.48 | 5 |
| 1992 | 44.06 | 6 |
| 1991 | 45.68 | 14 |
| 1990 | 47.32 | 20 |
| 1989 | 48.35 | 22 |
| 1988 | 49.12 | 24 |
| 1987 | 49.62 | 27 |
| 1986 | 49.79 | 27 |