| 时间 | 值 | 世界排名 |
|---|---|---|
| 2014 | 4.4 | 64 |
| 2013 | 4.2 | 78 |
| 2012 | 3.8 | 90 |
| 2011 | 3.1 | 109 |
| 2010 | 3.8 | 107 |
| 2009 | 4 | 104 |
| 2008 | 2.7 | 95 |
| 2007 | 3.9 | 74 |
| 2006 | 3.5 | 76 |
| 2005 | 3.1 | 78 |
| 2004 | 3.3 | 75 |
| 2003 | 4 | 65 |
| 2002 | 3.2 | 78 |
| 2001 | 3 | 74 |
| 2000 | 2.7 | 78 |
| 1999 | 1.1 | 130 |
| 1998 | 1.1 | 128 |
| 1997 | 1.3 | 125 |
| 1996 | 1.6 | 111 |
| 1995 | 0.7 | 135 |
| 1994 | 1.2 | 116 |
| 1993 | 1 | 120 |
| 1992 | 0.4 | 122 |
| 1991 | 0.6 | 118 |
| 1990 | 0.9 | 106 |
| 1989 | 1.3 | 97 |
| 1988 | 1.3 | 96 |
| 1987 | 1.4 | 94 |
| 1986 | 2.5 | 67 |