| 时间 | 值 | 世界排名 |
|---|---|---|
| 2015 | 5 | 54 |
| 2014 | 3.6 | 80 |
| 2013 | 4.3 | 73 |
| 2012 | 4.6 | 62 |
| 2011 | 4.4 | 59 |
| 2010 | 6.5 | 38 |
| 2009 | 6.4 | 49 |
| 2008 | 4.4 | 51 |
| 2007 | 5.4 | 44 |
| 2006 | 4.1 | 64 |
| 2005 | 2.3 | 111 |
| 2004 | 2.2 | 110 |
| 2003 | 2 | 112 |
| 2002 | 2.2 | 114 |
| 2001 | 1.2 | 127 |
| 2000 | 0.9 | 135 |
| 1999 | 0.1 | 144 |
| 1998 | 0 | 143 |
| 1997 | 0 | 144 |
| 1996 | 0.1 | 141 |
| 1995 | 0.1 | 139 |
| 1994 | 0.1 | 138 |
| 1993 | 0.1 | 133 |
| 1992 | 0.1 | 126 |
| 1991 | 0.2 | 122 |
| 1990 | 0.1 | 118 |
| 1989 | 0.4 | 114 |
| 1988 | 0.9 | 107 |
| 1987 | 0.3 | 115 |
| 1986 | 0.3 | 117 |