| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 73.13 | 100 |
| 2015 | 72.77 | 101 |
| 2014 | 72.34 | 103 |
| 2013 | 72.74 | 99 |
| 2012 | 67.77 | 142 |
| 2011 | 73.33 | 98 |
| 2010 | 74.48 | 93 |
| 2009 | 75.47 | 82 |
| 2008 | 76.16 | 77 |
| 2007 | 76.74 | 70 |
| 2006 | 77.25 | 68 |
| 2005 | 77.68 | 67 |
| 2004 | 78.03 | 66 |
| 2003 | 78.31 | 66 |
| 2002 | 78.61 | 67 |
| 2001 | 78.96 | 67 |
| 2000 | 79.34 | 66 |
| 1999 | 79.53 | 66 |
| 1998 | 79.64 | 65 |
| 1997 | 79.7 | 69 |
| 1996 | 79.77 | 72 |
| 1995 | 79.87 | 72 |
| 1994 | 79.8 | 75 |
| 1993 | 79.78 | 74 |
| 1992 | 79.73 | 73 |
| 1991 | 79.58 | 76 |
| 1990 | 79.34 | 76 |