| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 81.05 | 37 |
| 2015 | 80.98 | 38 |
| 2014 | 80.91 | 38 |
| 2013 | 81.31 | 35 |
| 2012 | 81.66 | 34 |
| 2011 | 82 | 30 |
| 2010 | 82.33 | 29 |
| 2009 | 82.71 | 27 |
| 2008 | 83.07 | 27 |
| 2007 | 83.42 | 25 |
| 2006 | 83.77 | 22 |
| 2005 | 84.12 | 23 |
| 2004 | 84.49 | 21 |
| 2003 | 84.87 | 19 |
| 2002 | 85.25 | 18 |
| 2001 | 85.64 | 16 |
| 2000 | 86.03 | 17 |
| 1999 | 86.36 | 15 |
| 1998 | 86.66 | 16 |
| 1997 | 86.93 | 16 |
| 1996 | 87.18 | 16 |
| 1995 | 87.53 | 15 |
| 1994 | 87.81 | 16 |
| 1993 | 88.06 | 17 |
| 1992 | 88.28 | 17 |
| 1991 | 88.46 | 17 |
| 1990 | 88.7 | 17 |