| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 72.16 | 25 |
| 2015 | 72.69 | 25 |
| 2014 | 73.21 | 25 |
| 2013 | 73.73 | 24 |
| 2012 | 74.24 | 24 |
| 2011 | 74.75 | 25 |
| 2010 | 75.25 | 25 |
| 2009 | 75.74 | 23 |
| 2008 | 76.23 | 23 |
| 2007 | 76.71 | 24 |
| 2006 | 77.18 | 23 |
| 2005 | 77.75 | 21 |
| 2004 | 78.31 | 19 |
| 2003 | 78.86 | 18 |
| 2002 | 79.4 | 18 |
| 2001 | 79.93 | 17 |
| 2000 | 80.45 | 17 |
| 1999 | 80.96 | 17 |
| 1998 | 81.46 | 17 |
| 1997 | 81.95 | 15 |
| 1996 | 82.43 | 15 |
| 1995 | 83.05 | 15 |
| 1994 | 83.68 | 13 |
| 1993 | 84.3 | 13 |
| 1992 | 84.89 | 12 |
| 1991 | 85.47 | 11 |
| 1990 | 86.03 | 11 |
| 1989 | 86.58 | 9 |
| 1988 | 87.1 | 9 |
| 1987 | 87.61 | 9 |
| 1986 | 88.1 | 9 |