| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 3.03 | 4 |
| 2015 | 3.03 | 4 |
| 2014 | 2.98 | 4 |
| 2013 | 2.92 | 4 |
| 2012 | 2.84 | 4 |
| 2011 | 2.77 | 4 |
| 2010 | 2.68 | 4 |
| 2009 | 2.7 | 3 |
| 2008 | 2.75 | 3 |
| 2007 | 2.84 | 3 |
| 2006 | 2.96 | 4 |
| 2005 | 3.11 | 4 |
| 2004 | 3.19 | 4 |
| 2003 | 3.27 | 4 |
| 2002 | 3.36 | 4 |
| 2001 | 3.49 | 4 |
| 2000 | 3.64 | 5 |
| 1999 | 3.66 | 4 |
| 1998 | 3.67 | 4 |
| 1997 | 3.66 | 4 |
| 1996 | 3.62 | 4 |
| 1995 | 3.56 | 5 |
| 1994 | 3.57 | 4 |
| 1993 | 3.56 | 4 |
| 1992 | 3.52 | 4 |
| 1991 | 3.44 | 5 |
| 1990 | 3.35 | 5 |
| 1989 | 3.47 | 5 |
| 1988 | 3.62 | 5 |
| 1987 | 3.78 | 5 |
| 1986 | 3.96 | 5 |