| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 64 | 55 |
| 2015 | 58.99 | 67 |
| 2014 | 62.71 | 59 |
| 2013 | 56.5 | 63 |
| 2012 | 58.88 | 55 |
| 2011 | 63.85 | 54 |
| 2010 | 71.68 | 43 |
| 2009 | 72.77 | 45 |
| 2008 | 64.66 | 49 |
| 2007 | 56.73 | 63 |
| 2006 | 61.71 | 48 |
| 2005 | 58.58 | 46 |
| 2004 | 58.79 | 47 |
| 2003 | 55.62 | 53 |
| 2002 | 58.74 | 47 |
| 2001 | 47.67 | 66 |
| 2000 | 50.34 | 51 |
| 1999 | 46.91 | 62 |
| 1998 | 41.22 | 66 |
| 1997 | 42.34 | 62 |
| 1996 | 31.57 | 88 |
| 1995 | 33.06 | 76 |
| 1994 | 28.2 | 93 |
| 1993 | 27.08 | 96 |
| 1992 | 24.41 | 99 |
| 1991 | 24.58 | 92 |
| 1990 | 20.55 | 104 |
| 1989 | 21.8 | 95 |
| 1988 | 18.32 | 107 |
| 1987 | 16.84 | 111 |
| 1986 | 19.63 | 100 |