| 时间 | 值 | 世界排名 |
|---|---|---|
| 2013 | 2.1 | 128 |
| 2012 | 3 | 114 |
| 2011 | 3.4 | 97 |
| 2010 | 3.4 | 112 |
| 2009 | 2.9 | 120 |
| 2008 | 2.4 | 105 |
| 2007 | 2.9 | 103 |
| 2006 | 2.8 | 102 |
| 2005 | 2.6 | 103 |
| 2004 | 3.7 | 68 |
| 2003 | 3.4 | 78 |
| 2002 | 2.5 | 101 |
| 2001 | 3.7 | 58 |
| 2000 | 2.8 | 74 |
| 1999 | 2.5 | 88 |
| 1998 | 1.9 | 100 |
| 1997 | 3.2 | 61 |
| 1996 | 2.5 | 77 |
| 1995 | 1.1 | 123 |
| 1994 | 0.8 | 128 |
| 1993 | 1 | 121 |
| 1992 | 1.1 | 113 |
| 1991 | 1.3 | 107 |
| 1990 | 1.1 | 100 |
| 1989 | 3.9 | 33 |
| 1988 | 3.5 | 41 |
| 1987 | 3.1 | 57 |
| 1986 | 2 | 83 |