| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 84.36 | 62 |
| 2015 | 85.99 | 77 |
| 2014 | 84.78 | 91 |
| 2013 | 84.96 | 93 |
| 2012 | 85.87 | 94 |
| 2011 | 84.75 | 99 |
| 2010 | 79.3 | 103 |
| 2009 | 70.67 | 113 |
| 2008 | 80.94 | 111 |
| 2007 | 79.37 | 113 |
| 2006 | 77.08 | 114 |
| 2005 | 70.42 | 121 |
| 2004 | 65.86 | 132 |
| 2003 | 61.52 | 133 |
| 2002 | 60.77 | 128 |
| 2001 | 61.98 | 121 |
| 2000 | 61.39 | 118 |
| 1999 | 53.37 | 125 |
| 1998 | 51.58 | 128 |
| 1997 | 49.6 | 137 |
| 1996 | 45 | 145 |
| 1995 | 43.54 | 150 |
| 1994 | 42.07 | 139 |
| 1993 | 40.64 | 134 |
| 1992 | 45.05 | 125 |
| 1991 | 47.97 | 114 |
| 1990 | 46.01 | 114 |
| 1989 | 45.36 | 102 |
| 1988 | 42.67 | 100 |
| 1987 | 41.83 | 102 |
| 1986 | 43.09 | 95 |