| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2013 | 31.12 | 46 |
| 2012 | 32.39 | 46 |
| 2011 | 33.29 | 41 |
| 2010 | 31.99 | 42 |
| 2009 | 32.42 | 41 |
| 2008 | 33.94 | 40 |
| 2007 | 36.56 | 37 |
| 2006 | 33.69 | 40 |
| 2005 | 30.52 | 38 |
| 2004 | 42.16 | 23 |
| 2003 | 36.71 | 26 |
| 2002 | 41.07 | 21 |
| 2001 | 41.68 | 22 |
| 2000 | 46.53 | 13 |
| 1999 | 46.77 | 16 |
| 1998 | 42.59 | 22 |
| 1997 | 41.78 | 20 |
| 1996 | 41.8 | 20 |
| 1995 | 40.51 | 22 |
| 1994 | 44.29 | 20 |
| 1993 | 41.6 | 22 |
| 1992 | 35.95 | 23 |
| 1991 | 36.13 | 23 |
| 1990 | 34.64 | 22 |
| 1989 | 31.35 | 25 |
| 1988 | 34.14 | 21 |
| 1987 | 34.2 | 21 |
| 1986 | 37.9 | 16 |