| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 53.81 | 101 |
| 2015 | 52.72 | 94 |
| 2014 | 52.16 | 90 |
| 2013 | 51.32 | 84 |
| 2012 | 50.47 | 81 |
| 2011 | 50.17 | 80 |
| 2010 | 50.73 | 84 |
| 2009 | 51.59 | 89 |
| 2008 | 53.26 | 95 |
| 2007 | 55.46 | 101 |
| 2006 | 57.6 | 105 |
| 2005 | 59.24 | 106 |
| 2004 | 61.26 | 111 |
| 2003 | 62.95 | 110 |
| 2002 | 64.42 | 109 |
| 2001 | 66.07 | 110 |
| 2000 | 68.19 | 113 |
| 1999 | 70.23 | 114 |
| 1998 | 72.32 | 114 |
| 1997 | 74.3 | 115 |
| 1996 | 75.98 | 115 |
| 1995 | 77.23 | 115 |
| 1994 | 78.39 | 114 |
| 1993 | 79.24 | 113 |
| 1992 | 79.79 | 114 |
| 1991 | 79.99 | 116 |
| 1990 | 79.73 | 114 |
| 1989 | 79.79 | 111 |
| 1988 | 79.71 | 108 |
| 1987 | 79.61 | 106 |
| 1986 | 79.68 | 105 |