| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2012 | 17 | 24 |
| 2011 | 17 | 22 |
| 2010 | 17 | 26 |
| 2009 | 19.5 | 20 |
| 2008 | 20.333 | 16 |
| 2007 | 23.5 | 11 |
| 2006 | 24 | 13 |
| 2005 | 23.083 | 17 |
| 2004 | 21 | 22 |
| 2003 | 21 | 23 |
| 2002 | 21 | 29 |
| 2001 | 22.5 | 30 |
| 2000 | 25.583 | 26 |
| 1999 | 28 | 26 |
| 1998 | 25.5 | 35 |
| 1997 | 22 | 44 |
| 1996 | 22 | 44 |
| 1995 | 20.333 | 43 |
| 1994 | 18.167 | 45 |
| 1993 | 17.583 | 46 |
| 1992 | 15.833 | 56 |
| 1991 | 10 | 84 |
| 1990 | 10 | 86 |
| 1989 | 10 | 85 |
| 1988 | 12 | 59 |
| 1987 | 12 | 53 |
| 1986 | 12 | 58 |