| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 77.73 | 66 |
| 2015 | 77.51 | 68 |
| 2014 | 77.31 | 70 |
| 2013 | 77.1 | 71 |
| 2012 | 76.86 | 75 |
| 2011 | 76.59 | 75 |
| 2010 | 76.29 | 77 |
| 2009 | 75.95 | 76 |
| 2008 | 75.58 | 82 |
| 2007 | 75.23 | 88 |
| 2006 | 74.93 | 92 |
| 2005 | 74.73 | 93 |
| 2004 | 74.59 | 90 |
| 2003 | 74.57 | 90 |
| 2002 | 74.65 | 92 |
| 2001 | 74.78 | 95 |
| 2000 | 74.91 | 94 |
| 1999 | 75.07 | 94 |
| 1998 | 75.24 | 96 |
| 1997 | 75.39 | 98 |
| 1996 | 75.53 | 98 |
| 1995 | 75.65 | 99 |
| 1994 | 75.7 | 98 |
| 1993 | 75.71 | 99 |
| 1992 | 75.67 | 102 |
| 1991 | 75.64 | 103 |
| 1990 | 75.64 | 110 |