| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 0.59 | 123 |
| 2015 | 0.61 | 135 |
| 2014 | 0.65 | 140 |
| 2013 | 0.68 | 136 |
| 2012 | 0.69 | 134 |
| 2011 | 0.73 | 125 |
| 2010 | 0.65 | 132 |
| 2009 | 0.83 | 125 |
| 2008 | 1.1 | 117 |
| 2007 | 1.12 | 112 |
| 2006 | 0.98 | 119 |
| 2005 | 1.07 | 119 |
| 2004 | 1.25 | 112 |
| 2003 | 1.32 | 106 |
| 2002 | 1.31 | 103 |
| 2001 | 1.44 | 93 |
| 2000 | 1.22 | 105 |
| 1999 | 1.21 | 106 |
| 1998 | 1.35 | 99 |
| 1997 | 1.48 | 94 |
| 1996 | 1.24 | 106 |
| 1995 | 0.86 | 126 |
| 1994 | 0.93 | 122 |
| 1993 | 1.12 | 117 |
| 1992 | 0.76 | 119 |
| 1991 | 1.31 | 97 |
| 1990 | 1.23 | 100 |
| 1989 | 1.21 | 99 |
| 1988 | 1.35 | 93 |
| 1987 | 1.43 | 93 |
| 1986 | 1.55 | 84 |