| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 30.52 | 22 |
| 2015 | 31.96 | 34 |
| 2014 | 33.19 | 35 |
| 2013 | 33.65 | 42 |
| 2012 | 34.14 | 40 |
| 2011 | 36.11 | 35 |
| 2010 | 31.81 | 43 |
| 2009 | 28.9 | 45 |
| 2008 | 31.97 | 42 |
| 2007 | 30.95 | 44 |
| 2006 | 31.28 | 41 |
| 2005 | 30.21 | 41 |
| 2004 | 27.64 | 47 |
| 2003 | 27.58 | 42 |
| 2002 | 27.13 | 43 |
| 2001 | 24.42 | 48 |
| 2000 | 25.09 | 42 |
| 1999 | 24.26 | 42 |
| 1998 | 26.66 | 38 |
| 1997 | 28.34 | 32 |
| 1996 | 26.64 | 32 |
| 1995 | 27.26 | 32 |
| 1994 | 26.36 | 34 |
| 1993 | 25.91 | 34 |
| 1992 | 26.66 | 32 |
| 1991 | 29.21 | 29 |
| 1990 | 27.71 | 27 |
| 1989 | 26.32 | 29 |
| 1988 | 26.8 | 29 |
| 1987 | 27.23 | 30 |
| 1986 | 28.79 | 26 |