| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 1.98 | 26 |
| 2015 | 2.05 | 28 |
| 2014 | 2.11 | 26 |
| 2013 | 2.17 | 24 |
| 2012 | 2.2 | 25 |
| 2011 | 2.22 | 29 |
| 2010 | 2.25 | 27 |
| 2009 | 2.27 | 22 |
| 2008 | 2.29 | 26 |
| 2007 | 2.32 | 27 |
| 2006 | 2.35 | 27 |
| 2005 | 2.39 | 22 |
| 2004 | 2.4 | 28 |
| 2003 | 2.39 | 29 |
| 2002 | 2.29 | 34 |
| 2001 | 2.15 | 35 |
| 2000 | 1.96 | 42 |
| 1999 | 1.79 | 50 |
| 1998 | 1.7 | 57 |
| 1997 | 1.74 | 57 |
| 1996 | 1.88 | 50 |
| 1995 | 2.09 | 45 |
| 1994 | 2.28 | 41 |
| 1993 | 2.4 | 40 |
| 1992 | 2.37 | 40 |
| 1991 | 2.23 | 44 |
| 1990 | 2.03 | 52 |
| 1989 | 1.86 | 60 |
| 1988 | 1.8 | 63 |
| 1987 | 1.91 | 58 |
| 1986 | 2.14 | 50 |