| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 82.7 | 30 |
| 2015 | 82.66 | 30 |
| 2014 | 82.57 | 30 |
| 2013 | 82.34 | 33 |
| 2012 | 82.07 | 31 |
| 2011 | 81.83 | 32 |
| 2010 | 81.63 | 32 |
| 2009 | 81.48 | 36 |
| 2008 | 81.42 | 37 |
| 2007 | 81.46 | 39 |
| 2006 | 81.58 | 40 |
| 2005 | 81.79 | 36 |
| 2004 | 82.09 | 36 |
| 2003 | 82.5 | 35 |
| 2002 | 82.97 | 30 |
| 2001 | 83.45 | 29 |
| 2000 | 83.9 | 24 |
| 1999 | 84.36 | 23 |
| 1998 | 84.72 | 20 |
| 1997 | 85.62 | 19 |
| 1996 | 86.44 | 19 |
| 1995 | 87.19 | 18 |
| 1994 | 88 | 15 |
| 1993 | 88.73 | 13 |
| 1992 | 89.39 | 13 |
| 1991 | 89.96 | 12 |
| 1990 | 90.46 | 11 |