| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 76.49 | 78 |
| 2015 | 76.51 | 77 |
| 2014 | 76.43 | 78 |
| 2013 | 76.38 | 78 |
| 2012 | 77.07 | 73 |
| 2011 | 77.01 | 72 |
| 2010 | 77.07 | 69 |
| 2009 | 76.53 | 72 |
| 2008 | 77.32 | 66 |
| 2007 | 76.62 | 72 |
| 2006 | 75.7 | 83 |
| 2005 | 74.27 | 96 |
| 2004 | 73.53 | 102 |
| 2003 | 72.41 | 113 |
| 2002 | 73.17 | 110 |
| 2001 | 76.55 | 81 |
| 2000 | 75.47 | 91 |
| 1999 | 77.13 | 81 |
| 1998 | 78.71 | 73 |
| 1997 | 79.48 | 71 |
| 1996 | 80.59 | 60 |
| 1995 | 72.4 | 123 |
| 1994 | 70.1 | 147 |
| 1993 | 71.04 | 143 |
| 1992 | 71.38 | 140 |
| 1991 | 71.47 | 142 |
| 1990 | 71.4 | 146 |