| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 2.86 | 3 |
| 2015 | 2.68 | 3 |
| 2014 | 2.63 | 3 |
| 2013 | 2.61 | 3 |
| 2012 | 2.62 | 3 |
| 2011 | 2.64 | 3 |
| 2010 | 2.67 | 3 |
| 2009 | 2.73 | 4 |
| 2008 | 2.8 | 4 |
| 2007 | 2.88 | 4 |
| 2006 | 2.95 | 3 |
| 2005 | 3 | 3 |
| 2004 | 2.85 | 3 |
| 2003 | 2.68 | 3 |
| 2002 | 2.52 | 3 |
| 2001 | 2.37 | 3 |
| 2000 | 2.25 | 2 |
| 1999 | 2.15 | 2 |
| 1998 | 2.07 | 2 |
| 1997 | 2.01 | 2 |
| 1996 | 1.98 | 2 |
| 1995 | 2 | 3 |
| 1991 | 2.17 | 3 |
| 1990 | 2.08 | 3 |
| 1989 | 2.14 | 3 |
| 1988 | 2.16 | 3 |
| 1987 | 2.17 | 3 |
| 1986 | 2.19 | 3 |