| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 83.71 | 64 |
| 2015 | 82.83 | 84 |
| 2014 | 82.82 | 94 |
| 2013 | 80.27 | 104 |
| 2012 | 79.9 | 107 |
| 2011 | 79.26 | 111 |
| 2010 | 70.74 | 121 |
| 2009 | 61.15 | 133 |
| 2008 | 67.12 | 135 |
| 2007 | 72.59 | 127 |
| 2006 | 76.05 | 115 |
| 2005 | 75.93 | 108 |
| 2004 | 80.21 | 99 |
| 2003 | 76.51 | 94 |
| 2002 | 76.05 | 96 |
| 2001 | 73.5 | 96 |
| 2000 | 70.71 | 103 |
| 1999 | 59.93 | 114 |
| 1998 | 53.48 | 124 |
| 1997 | 62.74 | 107 |
| 1996 | 60.38 | 106 |
| 1995 | 55.95 | 120 |
| 1994 | 51.87 | 117 |
| 1993 | 51 | 113 |
| 1992 | 63.99 | 83 |
| 1991 | 39.14 | 132 |
| 1990 | 42.91 | 124 |