| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 78.75 | 56 |
| 2015 | 78.55 | 56 |
| 2014 | 78.36 | 52 |
| 2013 | 78.17 | 52 |
| 2012 | 77.99 | 52 |
| 2011 | 77.81 | 52 |
| 2010 | 77.64 | 52 |
| 2009 | 77.48 | 52 |
| 2008 | 77.32 | 51 |
| 2007 | 77.18 | 51 |
| 2006 | 77.03 | 51 |
| 2005 | 76.9 | 51 |
| 2004 | 76.77 | 50 |
| 2003 | 76.66 | 50 |
| 2002 | 76.54 | 49 |
| 2001 | 76.44 | 49 |
| 2000 | 76.35 | 48 |
| 1999 | 76.26 | 47 |
| 1998 | 76.18 | 47 |
| 1997 | 76.11 | 47 |
| 1996 | 76.05 | 47 |
| 1995 | 75.99 | 46 |
| 1994 | 75.94 | 46 |
| 1993 | 75.89 | 46 |
| 1992 | 75.83 | 43 |
| 1991 | 75.78 | 41 |
| 1990 | 75.72 | 41 |
| 1989 | 75.67 | 41 |
| 1988 | 75.61 | 39 |
| 1987 | 75.56 | 39 |
| 1986 | 75.51 | 39 |