| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 83 | 9 |
| 2015 | 82.96 | 9 |
| 2014 | 82.94 | 9 |
| 2013 | 83.11 | 9 |
| 2012 | 83.28 | 7 |
| 2011 | 83.46 | 8 |
| 2010 | 83.64 | 6 |
| 2009 | 83.83 | 6 |
| 2008 | 84.03 | 5 |
| 2007 | 84.21 | 5 |
| 2006 | 84.38 | 5 |
| 2005 | 84.53 | 6 |
| 2004 | 83.98 | 7 |
| 2003 | 83.39 | 9 |
| 2002 | 82.76 | 8 |
| 2001 | 82.1 | 11 |
| 2000 | 81.43 | 10 |
| 1999 | 80.71 | 12 |
| 1998 | 80.76 | 12 |
| 1997 | 80.73 | 12 |
| 1996 | 80.77 | 13 |
| 1995 | 80.9 | 13 |
| 1994 | 80.93 | 14 |
| 1993 | 80.92 | 14 |
| 1992 | 81 | 14 |
| 1991 | 80.87 | 14 |
| 1990 | 80.76 | 15 |