| 时间 | 值 | 世界排名 |
|---|---|---|
| 2016 | 17.1 | 3 |
| 2015 | 14.4 | 7 |
| 2014 | 11.4 | 12 |
| 2013 | 11.6 | 11 |
| 2012 | 12.2 | 11 |
| 2011 | 10.7 | 14 |
| 2010 | 10.5 | 18 |
| 2009 | 13.2 | 12 |
| 2008 | 8.5 | 17 |
| 2007 | 10.9 | 14 |
| 2006 | 6.7 | 27 |
| 2005 | 5.1 | 36 |
| 2004 | 6.2 | 25 |
| 2003 | 7 | 22 |
| 2002 | 5.5 | 37 |
| 2001 | 4.5 | 41 |
| 2000 | 4.3 | 44 |
| 1999 | 5.1 | 36 |
| 1998 | 5.3 | 25 |
| 1997 | 6.4 | 9 |
| 1996 | 8.6 | 6 |
| 1995 | 7.9 | 6 |
| 1994 | 8.4 | 8 |
| 1993 | 8.2 | 6 |
| 1992 | 7.5 | 8 |
| 1991 | 2.7 | 65 |
| 1990 | 2.7 | 59 |
| 1989 | 2.8 | 61 |
| 1988 | 3 | 51 |
| 1987 | 3 | 59 |
| 1986 | 2.7 | 65 |