| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 1.94 | 31 |
| 2015 | 1.99 | 34 |
| 2014 | 2.04 | 31 |
| 2013 | 2.08 | 31 |
| 2012 | 2.11 | 31 |
| 2011 | 2.13 | 35 |
| 2010 | 2.15 | 34 |
| 2009 | 2.17 | 29 |
| 2008 | 2.19 | 30 |
| 2007 | 2.43 | 21 |
| 2006 | 2.49 | 20 |
| 2005 | 2.55 | 16 |
| 2004 | 2.6 | 20 |
| 2003 | 2.64 | 21 |
| 2002 | 2.66 | 20 |
| 2001 | 2.68 | 18 |
| 2000 | 2.67 | 21 |
| 1999 | 2.68 | 23 |
| 1998 | 2.72 | 22 |
| 1997 | 2.82 | 16 |
| 1996 | 2.96 | 16 |
| 1995 | 3.1 | 16 |
| 1994 | 3.19 | 14 |
| 1993 | 3.29 | 12 |
| 1992 | 3.31 | 10 |
| 1991 | 3.26 | 12 |
| 1990 | 3.17 | 13 |
| 1989 | 3.07 | 13 |
| 1988 | 2.99 | 19 |
| 1987 | 2.95 | 20 |
| 1986 | 2.93 | 21 |