| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 77.38 | 17 |
| 2015 | 77.53 | 18 |
| 2014 | 77.66 | 17 |
| 2013 | 77.77 | 17 |
| 2012 | 77.87 | 17 |
| 2011 | 77.95 | 18 |
| 2010 | 78.02 | 18 |
| 2009 | 78.07 | 18 |
| 2008 | 78.1 | 18 |
| 2007 | 78.13 | 19 |
| 2006 | 78.17 | 17 |
| 2005 | 78.2 | 19 |
| 2004 | 78.23 | 20 |
| 2003 | 78.27 | 20 |
| 2002 | 78.3 | 19 |
| 2001 | 78.33 | 20 |
| 2000 | 78.36 | 20 |
| 1999 | 78.4 | 22 |
| 1998 | 78.43 | 22 |
| 1997 | 78.46 | 23 |
| 1996 | 78.49 | 24 |
| 1995 | 78.53 | 24 |
| 1994 | 78.56 | 26 |
| 1993 | 78.59 | 27 |
| 1992 | 78.77 | 26 |
| 1991 | 78.98 | 26 |
| 1990 | 79.19 | 26 |
| 1989 | 79.4 | 28 |
| 1988 | 79.61 | 28 |
| 1987 | 79.81 | 28 |
| 1986 | 80.02 | 29 |