| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2011 | 5.92 | 119 |
| 2010 | 5.383 | 129 |
| 2009 | 5.743 | 126 |
| 2008 | 7.893 | 116 |
| 2007 | 7.583 | 124 |
| 2006 | 6.709 | 133 |
| 2005 | 7.175 | 119 |
| 2004 | 7.138 | 119 |
| 2003 | 7.488 | 113 |
| 2002 | 7.95 | 116 |
| 2001 | 8.8 | 112 |
| 2000 | 9.2 | 117 |
| 1999 | 7.925 | 127 |
| 1998 | 9.525 | 117 |
| 1997 | 11.425 | 97 |
| 1996 | 14.45 | 82 |
| 1995 | 15.225 | 76 |
| 1994 | 15 | 65 |
| 1993 | 16 | 59 |
| 1992 | 17.9 | 43 |
| 1991 | 15.2 | 54 |
| 1990 | 14.5 | 51 |