| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2015 | 8.14 | 32 |
| 2014 | 9.88 | 21 |
| 2013 | 8.18 | 27 |
| 2012 | -.15 | 182 |
| 2011 | 10.16 | 29 |
| 2010 | 1.39 | 145 |
| 2009 | 0.79 | 154 |
| 2008 | 3.67 | 110 |
| 2007 | 2.81 | 133 |
| 2006 | 0.89 | 164 |
| 2005 | 3.82 | 84 |
| 2004 | 3.1 | 94 |
| 2003 | 2.05 | 103 |
| 2002 | 0.17 | 165 |
| 2001 | 1.12 | 125 |
| 2000 | 1.49 | 118 |
| 1999 | 3.3 | 76 |
| 1998 | 0.69 | 137 |
| 1997 | 0.56 | 137 |
| 1996 | 0.69 | 120 |
| 1995 | 0.4 | 133 |
| 1994 | 2.11 | 52 |
| 1993 | 0.39 | 110 |
| 1992 | -.39 | 145 |
| 1991 | -1.3 | 147 |
| 1990 | 1.24 | 57 |
| 1989 | 0.58 | 72 |
| 1988 | 1.26 | 41 |
| 1987 | 0.01 | 117 |
| 1986 | -.25 | 124 |