| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 35.25 | 23 |
| 2015 | 33.82 | 35 |
| 2014 | 34.74 | 39 |
| 2013 | 34.42 | 41 |
| 2012 | 34.62 | 43 |
| 2011 | 35.84 | 43 |
| 2010 | 36.98 | 38 |
| 2009 | 33.02 | 48 |
| 2008 | 34.38 | 47 |
| 2007 | 41.89 | 25 |
| 2006 | 43.02 | 23 |
| 2005 | 36.21 | 36 |
| 2004 | 31.98 | 57 |
| 2003 | 28.4 | 78 |
| 2002 | 25.55 | 99 |
| 2001 | 25.17 | 102 |
| 2000 | 24.99 | 102 |
| 1999 | 24.46 | 107 |
| 1998 | 24.46 | 104 |
| 1997 | 30.73 | 63 |
| 1996 | 25.19 | 103 |
| 1995 | 34.68 | 35 |
| 1994 | 33.48 | 43 |
| 1993 | 32.55 | 51 |
| 1992 | 36.91 | 36 |
| 1991 | 38.09 | 28 |
| 1990 | 42.48 | 22 |
| 1989 | 38.79 | 25 |
| 1988 | 28.82 | 58 |
| 1987 | 28.39 | 56 |
| 1986 | 28.28 | 52 |