| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 82.6 | 13 |
| 2015 | 82.63 | 13 |
| 2014 | 82.8 | 13 |
| 2013 | 83.65 | 13 |
| 2012 | 83.94 | 14 |
| 2011 | 84.22 | 11 |
| 2010 | 81.89 | 18 |
| 2009 | 84.67 | 12 |
| 2008 | 84.48 | 13 |
| 2007 | 84.15 | 13 |
| 2006 | 83.93 | 13 |
| 2005 | 85.38 | 11 |
| 2004 | 86.67 | 9 |
| 2003 | 84.17 | 11 |
| 2002 | 81.07 | 20 |
| 2001 | 77.67 | 41 |
| 2000 | 76.81 | 42 |
| 1999 | 73.14 | 65 |
| 1998 | 73.19 | 65 |
| 1997 | 73.32 | 66 |
| 1996 | 74.48 | 61 |
| 1995 | 75.04 | 59 |
| 1994 | 75.48 | 60 |
| 1993 | 74.48 | 66 |
| 1992 | 74.43 | 66 |
| 1991 | 74.3 | 68 |