| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 1.8 | 35 |
| 2015 | 1.84 | 36 |
| 2014 | 1.87 | 34 |
| 2013 | 1.9 | 35 |
| 2012 | 1.92 | 36 |
| 2011 | 1.93 | 39 |
| 2010 | 1.96 | 40 |
| 2009 | 1.98 | 41 |
| 2008 | 1.93 | 49 |
| 2007 | 1.75 | 51 |
| 2006 | 1.48 | 62 |
| 2005 | 1.15 | 73 |
| 2004 | 0.87 | 91 |
| 2003 | 0.76 | 96 |
| 2002 | 0.91 | 85 |
| 2001 | 1.24 | 74 |
| 2000 | 1.67 | 53 |
| 1999 | 2.07 | 41 |
| 1998 | 2.34 | 29 |
| 1997 | 2.23 | 38 |
| 1996 | 2.12 | 44 |
| 1995 | 1.96 | 52 |
| 1994 | 1.87 | 53 |
| 1993 | 1.93 | 55 |
| 1992 | 2.24 | 44 |
| 1991 | 2.74 | 27 |
| 1990 | 3.35 | 10 |
| 1989 | 3.91 | 7 |
| 1988 | 4.27 | 6 |
| 1987 | 4.12 | 9 |
| 1986 | 2.94 | 20 |