| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 68.1 | 89 |
| 2015 | 78.95 | 88 |
| 2014 | 74.67 | 114 |
| 2013 | 72.58 | 122 |
| 2012 | 72.98 | 123 |
| 2011 | 69.08 | 133 |
| 2010 | 68.02 | 128 |
| 2009 | 74 | 104 |
| 2008 | 83.45 | 106 |
| 2007 | 82.39 | 108 |
| 2006 | 75.5 | 116 |
| 2005 | 73.77 | 111 |
| 2004 | 80.12 | 100 |
| 2003 | 55.16 | 141 |
| 2002 | 38.58 | 169 |
| 2001 | 61.37 | 122 |
| 2000 | 68.68 | 106 |
| 1999 | 56.68 | 118 |
| 1998 | 50.8 | 131 |
| 1997 | 51.83 | 130 |
| 1996 | 46.5 | 141 |
| 1995 | 55.85 | 121 |
| 1994 | 51.63 | 118 |
| 1993 | 39.93 | 137 |
| 1992 | 41.05 | 132 |
| 1991 | 44.8 | 119 |
| 1990 | 44.63 | 120 |
| 1989 | 40.72 | 115 |
| 1988 | 39.4 | 109 |
| 1987 | 39.07 | 107 |
| 1986 | 27.7 | 125 |