| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 68.01 | 90 |
| 2015 | 67.15 | 117 |
| 2014 | 76.63 | 105 |
| 2013 | 72.65 | 121 |
| 2012 | 80.58 | 105 |
| 2011 | 80.68 | 108 |
| 2010 | 80.39 | 101 |
| 2009 | 77.11 | 97 |
| 2008 | 80.29 | 114 |
| 2007 | 84.73 | 100 |
| 2006 | 95.91 | 72 |
| 2005 | 85.85 | 90 |
| 2004 | 101.77 | 55 |
| 2003 | 83.38 | 82 |
| 2002 | 126.35 | 24 |
| 2001 | 64.32 | 116 |
| 2000 | 51.57 | 143 |
| 1999 | 50.51 | 132 |
| 1998 | 48.06 | 142 |
| 1997 | 49.31 | 139 |
| 1996 | 46.61 | 140 |
| 1995 | 55.7 | 122 |
| 1994 | 50.99 | 119 |
| 1993 | 42.65 | 132 |
| 1992 | 35.9 | 142 |
| 1991 | 36.35 | 138 |
| 1990 | 41.39 | 129 |
| 1989 | 45.19 | 103 |
| 1988 | 45.12 | 95 |
| 1987 | 51.88 | 78 |
| 1986 | 48.77 | 86 |