| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 3.64 | 38 |
| 2015 | 3.67 | 42 |
| 2014 | 3.7 | 40 |
| 2013 | 3.69 | 43 |
| 2012 | 3.65 | 44 |
| 2011 | 3.57 | 48 |
| 2010 | 3.47 | 52 |
| 2009 | 3.37 | 52 |
| 2008 | 3.28 | 58 |
| 2007 | 3.2 | 63 |
| 2006 | 3.14 | 67 |
| 2005 | 3.09 | 69 |
| 2004 | 3.03 | 67 |
| 2003 | 2.96 | 68 |
| 2002 | 2.92 | 71 |
| 2001 | 2.86 | 71 |
| 2000 | 2.8 | 73 |
| 1999 | 2.75 | 76 |
| 1998 | 2.75 | 80 |
| 1997 | 2.81 | 75 |
| 1996 | 2.93 | 76 |
| 1995 | 3.08 | 69 |
| 1994 | 3.23 | 66 |
| 1993 | 3.34 | 67 |
| 1992 | 3.4 | 73 |
| 1991 | 3.42 | 76 |
| 1990 | 3.42 | 79 |
| 1989 | 3.43 | 85 |
| 1988 | 3.95 | 72 |
| 1987 | 4.01 | 72 |
| 1986 | 4.01 | 73 |