| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 77.41 | 69 |
| 2015 | 77.04 | 74 |
| 2014 | 76.7 | 74 |
| 2013 | 76.69 | 75 |
| 2012 | 76.75 | 76 |
| 2011 | 76.83 | 73 |
| 2010 | 76.98 | 70 |
| 2009 | 77.26 | 69 |
| 2008 | 77.55 | 64 |
| 2007 | 77.92 | 63 |
| 2006 | 78.31 | 62 |
| 2005 | 78.78 | 60 |
| 2004 | 79.28 | 57 |
| 2003 | 79.73 | 56 |
| 2002 | 80.14 | 58 |
| 2001 | 80.51 | 55 |
| 2000 | 80.82 | 55 |
| 1999 | 81.12 | 52 |
| 1998 | 81.47 | 52 |
| 1997 | 81.58 | 51 |
| 1996 | 81.84 | 50 |
| 1995 | 82.08 | 49 |
| 1994 | 82.3 | 46 |
| 1993 | 82.57 | 45 |
| 1992 | 82.71 | 44 |
| 1991 | 82.82 | 46 |
| 1990 | 82.87 | 47 |