| 时间 | 值 | 世界排名 |
|---|---|---|
| 2015 | 13.7 | 10 |
| 2014 | 12.7 | 8 |
| 2013 | 11.5 | 13 |
| 2012 | 9.8 | 14 |
| 2011 | 8.3 | 20 |
| 2010 | 7.6 | 29 |
| 2009 | 9.9 | 19 |
| 2008 | 6.4 | 28 |
| 2007 | 6 | 37 |
| 2006 | 5.3 | 37 |
| 2005 | 6.4 | 25 |
| 2004 | 6.4 | 23 |
| 2003 | 7.2 | 20 |
| 2002 | 3.3 | 76 |
| 2001 | 8 | 8 |
| 2000 | 6.6 | 12 |
| 1999 | 6.4 | 13 |
| 1998 | 5.9 | 17 |
| 1997 | 4.8 | 30 |
| 1996 | 4.9 | 28 |
| 1995 | 5.2 | 22 |
| 1994 | 4.9 | 31 |
| 1993 | 5.2 | 22 |
| 1992 | 4.9 | 23 |
| 1991 | 5.6 | 16 |
| 1990 | 7.7 | 7 |
| 1989 | 8.8 | 6 |
| 1988 | 10.3 | 3 |
| 1987 | 11.7 | 4 |
| 1986 | 11.3 | 4 |