| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 79.52 | 54 |
| 2015 | 79.25 | 53 |
| 2014 | 78.97 | 51 |
| 2013 | 78.69 | 51 |
| 2012 | 78.41 | 51 |
| 2011 | 78.12 | 51 |
| 2010 | 77.83 | 51 |
| 2009 | 77.53 | 51 |
| 2008 | 77.23 | 52 |
| 2007 | 76.92 | 52 |
| 2006 | 76.62 | 53 |
| 2005 | 76.31 | 53 |
| 2004 | 76 | 54 |
| 2003 | 75.68 | 53 |
| 2002 | 75.37 | 53 |
| 2001 | 75.05 | 53 |
| 2000 | 74.72 | 53 |
| 1999 | 74.44 | 53 |
| 1998 | 74.19 | 54 |
| 1997 | 73.93 | 54 |
| 1996 | 73.67 | 53 |
| 1995 | 73.37 | 55 |
| 1994 | 72.99 | 56 |
| 1993 | 72.6 | 56 |
| 1992 | 72.21 | 55 |
| 1991 | 71.82 | 55 |
| 1990 | 71.42 | 56 |
| 1989 | 70.96 | 57 |
| 1988 | 70.46 | 55 |
| 1987 | 69.96 | 54 |
| 1986 | 69.46 | 53 |