| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 59.3 | 125 |
| 2015 | 60.25 | 127 |
| 2014 | 61.16 | 127 |
| 2013 | 62.3 | 129 |
| 2012 | 63.64 | 131 |
| 2011 | 65.1 | 131 |
| 2010 | 66.61 | 133 |
| 2009 | 68.65 | 133 |
| 2008 | 70.89 | 137 |
| 2007 | 73.29 | 140 |
| 2006 | 75.8 | 142 |
| 2005 | 78.35 | 143 |
| 2004 | 80.72 | 148 |
| 2003 | 82.9 | 150 |
| 2002 | 84.85 | 152 |
| 2001 | 86.67 | 156 |
| 2000 | 88.49 | 160 |
| 1999 | 89.9 | 161 |
| 1998 | 91.08 | 161 |
| 1997 | 91.97 | 161 |
| 1996 | 92.41 | 162 |
| 1995 | 92.29 | 161 |
| 1994 | 92.71 | 157 |
| 1993 | 92.77 | 155 |
| 1992 | 92.55 | 154 |
| 1991 | 92.14 | 154 |
| 1990 | 91.54 | 149 |
| 1989 | 91.85 | 145 |
| 1988 | 92.13 | 142 |
| 1987 | 92.34 | 141 |
| 1986 | 92.46 | 144 |