| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 79.81 | 48 |
| 2015 | 79.7 | 48 |
| 2014 | 79.59 | 48 |
| 2013 | 79.59 | 49 |
| 2012 | 79.26 | 53 |
| 2011 | 80.24 | 47 |
| 2010 | 80.59 | 46 |
| 2009 | 82.39 | 31 |
| 2008 | 83.28 | 25 |
| 2007 | 84.08 | 21 |
| 2006 | 85.73 | 15 |
| 2005 | 84.63 | 20 |
| 2004 | 84.69 | 20 |
| 2003 | 84.2 | 22 |
| 2002 | 84.28 | 22 |
| 2001 | 84.34 | 22 |
| 2000 | 84.39 | 21 |
| 1999 | 84.46 | 20 |
| 1998 | 84.54 | 21 |
| 1997 | 84.57 | 22 |
| 1996 | 84.59 | 24 |
| 1995 | 84.62 | 27 |
| 1994 | 84.61 | 28 |
| 1993 | 84.59 | 29 |
| 1992 | 84.58 | 31 |
| 1991 | 84.56 | 32 |
| 1990 | 84.53 | 33 |