| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 27.72 | 55 |
| 2015 | 27.41 | 52 |
| 2014 | 26.87 | 46 |
| 2013 | 26.27 | 44 |
| 2012 | 25.75 | 41 |
| 2011 | 25.41 | 41 |
| 2010 | 25.29 | 38 |
| 2009 | 25.36 | 37 |
| 2008 | 25.71 | 36 |
| 2007 | 26.2 | 37 |
| 2006 | 26.58 | 37 |
| 2005 | 26.66 | 35 |
| 2004 | 27.1 | 34 |
| 2003 | 27.4 | 33 |
| 2002 | 27.63 | 29 |
| 2001 | 27.99 | 30 |
| 2000 | 28.66 | 31 |
| 1999 | 28.95 | 28 |
| 1998 | 29.28 | 28 |
| 1997 | 29.59 | 26 |
| 1996 | 29.72 | 23 |
| 1995 | 29.6 | 21 |
| 1994 | 29.39 | 21 |
| 1993 | 29.06 | 20 |
| 1992 | 28.67 | 15 |
| 1991 | 28.28 | 11 |
| 1990 | 27.9 | 11 |
| 1989 | 27.76 | 11 |
| 1988 | 27.71 | 10 |
| 1987 | 27.75 | 10 |
| 1986 | 27.89 | 10 |