| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 84.17 | 63 |
| 2015 | 86.43 | 76 |
| 2014 | 85.75 | 87 |
| 2013 | 83.09 | 98 |
| 2012 | 87.72 | 93 |
| 2011 | 88.66 | 92 |
| 2010 | 86.9 | 88 |
| 2009 | 83.14 | 92 |
| 2008 | 93.36 | 85 |
| 2007 | 89.54 | 88 |
| 2006 | 88.79 | 92 |
| 2005 | 84.57 | 95 |
| 2004 | 79.29 | 104 |
| 2003 | 76.15 | 97 |
| 2002 | 77.86 | 91 |
| 2001 | 81.28 | 80 |
| 2000 | 82.33 | 82 |
| 1999 | 76.01 | 87 |
| 1998 | 75.74 | 90 |
| 1997 | 73.15 | 95 |
| 1996 | 67.49 | 98 |
| 1995 | 69.63 | 91 |
| 1994 | 64.93 | 91 |
| 1993 | 59.24 | 93 |
| 1992 | 51.72 | 111 |
| 1991 | 52.05 | 102 |
| 1990 | 56.86 | 94 |
| 1989 | 60.13 | 77 |
| 1988 | 59.44 | 70 |
| 1987 | 59.78 | 66 |
| 1986 | 59.34 | 65 |