| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 82.59 | 47 |
| 2015 | 82.47 | 47 |
| 2014 | 82.36 | 44 |
| 2013 | 82.25 | 44 |
| 2012 | 82.14 | 44 |
| 2011 | 82.04 | 44 |
| 2010 | 81.94 | 44 |
| 2009 | 81.84 | 44 |
| 2008 | 81.73 | 42 |
| 2007 | 81.63 | 42 |
| 2006 | 81.53 | 41 |
| 2005 | 81.35 | 41 |
| 2004 | 81 | 41 |
| 2003 | 80.65 | 40 |
| 2002 | 80.3 | 42 |
| 2001 | 79.94 | 42 |
| 2000 | 79.62 | 41 |
| 1999 | 79.38 | 40 |
| 1998 | 79.15 | 40 |
| 1997 | 78.91 | 40 |
| 1996 | 78.66 | 37 |
| 1995 | 78.24 | 40 |
| 1994 | 77.45 | 41 |
| 1993 | 76.65 | 42 |
| 1992 | 75.82 | 44 |
| 1991 | 74.97 | 46 |
| 1990 | 73.84 | 48 |
| 1989 | 72.15 | 51 |
| 1988 | 70.39 | 56 |
| 1987 | 68.56 | 58 |
| 1986 | 66.68 | 64 |