| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 79.75 | 53 |
| 2015 | 79.52 | 52 |
| 2014 | 79.29 | 50 |
| 2013 | 79.06 | 50 |
| 2012 | 78.82 | 50 |
| 2011 | 78.58 | 50 |
| 2010 | 78.35 | 50 |
| 2009 | 78.11 | 50 |
| 2008 | 77.86 | 50 |
| 2007 | 77.62 | 50 |
| 2006 | 77.38 | 50 |
| 2005 | 77.13 | 50 |
| 2004 | 76.88 | 49 |
| 2003 | 76.63 | 51 |
| 2002 | 76.38 | 51 |
| 2001 | 76.13 | 51 |
| 2000 | 75.87 | 51 |
| 1999 | 75.61 | 50 |
| 1998 | 75.42 | 49 |
| 1997 | 75.25 | 49 |
| 1996 | 75.08 | 49 |
| 1995 | 74.91 | 49 |
| 1994 | 74.74 | 49 |
| 1993 | 74.57 | 49 |
| 1992 | 74.4 | 49 |
| 1991 | 74.23 | 49 |
| 1990 | 74.06 | 46 |
| 1989 | 73.95 | 45 |
| 1988 | 73.88 | 45 |
| 1987 | 73.8 | 45 |
| 1986 | 73.73 | 45 |