| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 53.27 | 96 |
| 2015 | 54.13 | 104 |
| 2014 | 55 | 107 |
| 2013 | 56.1 | 112 |
| 2012 | 57.39 | 119 |
| 2011 | 58.74 | 121 |
| 2010 | 60.06 | 122 |
| 2009 | 61.37 | 123 |
| 2008 | 62.68 | 123 |
| 2007 | 64.05 | 122 |
| 2006 | 65.58 | 121 |
| 2005 | 67.32 | 122 |
| 2004 | 68.97 | 123 |
| 2003 | 70.78 | 124 |
| 2002 | 72.73 | 125 |
| 2001 | 74.78 | 125 |
| 2000 | 76.89 | 127 |
| 1999 | 78.99 | 127 |
| 1998 | 81.14 | 129 |
| 1997 | 83.3 | 133 |
| 1996 | 85.42 | 137 |
| 1995 | 87.49 | 141 |
| 1994 | 89.42 | 145 |
| 1993 | 91.19 | 148 |
| 1992 | 92.82 | 155 |
| 1991 | 94.37 | 160 |
| 1990 | 95.87 | 163 |
| 1989 | 96.89 | 163 |
| 1988 | 97.83 | 165 |
| 1987 | 98.65 | 168 |
| 1986 | 99.23 | 171 |