| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 31.71 | 40 |
| 2015 | 34.65 | 30 |
| 2014 | 38.07 | 23 |
| 2013 | 39.82 | 23 |
| 2012 | 41.1 | 23 |
| 2011 | 41.41 | 23 |
| 2010 | 39.07 | 29 |
| 2009 | 38.42 | 24 |
| 2008 | 44.8 | 19 |
| 2007 | 41.91 | 24 |
| 2006 | 44.48 | 22 |
| 2005 | 42.58 | 21 |
| 2004 | 39.44 | 25 |
| 2003 | 37.71 | 26 |
| 2002 | 37.69 | 28 |
| 2001 | 39.85 | 24 |
| 2000 | 41.38 | 19 |
| 1999 | 34.07 | 36 |
| 1998 | 31.94 | 48 |
| 1997 | 36.28 | 27 |
| 1996 | 35.7 | 31 |
| 1995 | 33.2 | 47 |
| 1994 | 31.99 | 56 |
| 1993 | 31.41 | 58 |
| 1992 | 31.71 | 55 |
| 1991 | 32.02 | 55 |
| 1990 | 33.23 | 47 |
| 1989 | 32.96 | 46 |
| 1988 | 31.37 | 49 |
| 1987 | 32.94 | 44 |
| 1986 | 33.77 | 35 |