| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 0.76 | 61 |
| 2015 | 0.48 | 166 |
| 2014 | 1.65 | 128 |
| 2013 | 2.25 | 112 |
| 2012 | 1.17 | 156 |
| 2011 | 0.99 | 156 |
| 2010 | 0.98 | 153 |
| 2009 | 2.58 | 105 |
| 2008 | 3.45 | 113 |
| 2007 | 2.2 | 147 |
| 2006 | 0.23 | 176 |
| 2005 | 2.53 | 108 |
| 2004 | 0.31 | 165 |
| 2003 | 0.45 | 162 |
| 2002 | 1.28 | 122 |
| 2001 | 5.98 | 32 |
| 2000 | 0.71 | 138 |
| 1999 | 1.1 | 119 |
| 1998 | 0.4 | 147 |
| 1997 | 2.5 | 76 |
| 1996 | 0.55 | 130 |
| 1995 | 0.8 | 102 |
| 1994 | 0.27 | 124 |
| 1993 | 0.01 | 140 |
| 1992 | 0 | 131 |
| 1991 | 0.21 | 112 |
| 1990 | -.07 | 133 |
| 1989 | -.16 | 129 |
| 1988 | 0.13 | 101 |
| 1987 | -.18 | 126 |
| 1986 | -.06 | 118 |