| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 68.45 | 87 |
| 2015 | 74.76 | 99 |
| 2014 | 85.48 | 89 |
| 2013 | 84.09 | 95 |
| 2012 | 83.07 | 102 |
| 2011 | 80.57 | 109 |
| 2010 | 74.22 | 113 |
| 2009 | 70.97 | 112 |
| 2008 | 76.23 | 124 |
| 2007 | 82.46 | 107 |
| 2006 | 86.32 | 100 |
| 2005 | 80.66 | 100 |
| 2004 | 77.51 | 106 |
| 2003 | 66.73 | 119 |
| 2002 | 66.28 | 116 |
| 2001 | 66.3 | 110 |
| 2000 | 74.31 | 96 |
| 1999 | 80.06 | 79 |
| 1998 | 84.27 | 74 |
| 1997 | 65.16 | 104 |
| 1996 | 63.76 | 103 |
| 1995 | 60.55 | 110 |
| 1994 | 64.81 | 94 |
| 1993 | 52.63 | 111 |
| 1992 | 44.13 | 127 |
| 1991 | 38.18 | 136 |
| 1990 | 35.85 | 139 |
| 1989 | 44.13 | 108 |
| 1988 | 45.53 | 93 |
| 1987 | 20.12 | 131 |
| 1986 | 11.32 | 139 |