| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 79.48 | 26 |
| 2015 | 79.63 | 26 |
| 2014 | 79.65 | 26 |
| 2013 | 79.87 | 25 |
| 2012 | 80.67 | 25 |
| 2011 | 80.8 | 21 |
| 2010 | 80.13 | 24 |
| 2009 | 80.29 | 24 |
| 2008 | 80.61 | 22 |
| 2007 | 80.83 | 19 |
| 2006 | 80.24 | 25 |
| 2005 | 80.21 | 23 |
| 2004 | 80.51 | 19 |
| 2003 | 79.8 | 24 |
| 2002 | 79.83 | 24 |
| 2001 | 79.35 | 29 |
| 2000 | 78.88 | 36 |
| 1999 | 78.07 | 38 |
| 1998 | 78.79 | 36 |
| 1997 | 81.4 | 24 |
| 1996 | 81.47 | 23 |
| 1995 | 81.9 | 23 |
| 1994 | 82.4 | 22 |
| 1993 | 83.1 | 22 |
| 1992 | 84.18 | 19 |
| 1991 | 84 | 19 |