| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 78.69 | 15 |
| 2015 | 78.69 | 15 |
| 2014 | 78.69 | 15 |
| 2013 | 78.66 | 15 |
| 2012 | 78.63 | 16 |
| 2011 | 78.58 | 17 |
| 2010 | 78.51 | 17 |
| 2009 | 78.43 | 17 |
| 2008 | 78.33 | 17 |
| 2007 | 78.22 | 18 |
| 2006 | 78.09 | 18 |
| 2005 | 77.96 | 20 |
| 2004 | 77.83 | 21 |
| 2003 | 77.7 | 22 |
| 2002 | 77.58 | 24 |
| 2001 | 77.45 | 24 |
| 2000 | 77.31 | 26 |
| 1999 | 77.18 | 26 |
| 1998 | 77.05 | 26 |
| 1997 | 76.92 | 29 |
| 1996 | 76.92 | 30 |
| 1995 | 76.95 | 30 |
| 1994 | 76.98 | 30 |
| 1993 | 77.01 | 31 |
| 1992 | 77.04 | 31 |
| 1991 | 77.07 | 31 |
| 1990 | 77.09 | 31 |
| 1989 | 77.12 | 31 |
| 1988 | 77.15 | 34 |
| 1987 | 77.18 | 34 |
| 1986 | 77.33 | 34 |