| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2015 | 0.74 | 157 |
| 2014 | 4.27 | 62 |
| 2013 | 7.21 | 33 |
| 2012 | 8.29 | 36 |
| 2011 | 4.79 | 70 |
| 2010 | 12.9 | 23 |
| 2009 | -1.92 | 184 |
| 2008 | 19.04 | 12 |
| 2007 | 29.21 | 7 |
| 2006 | 19.72 | 14 |
| 2005 | 14.68 | 15 |
| 2004 | 7.29 | 35 |
| 2003 | 6.18 | 37 |
| 2002 | 5.38 | 42 |
| 2001 | 2.35 | 91 |
| 2000 | -.01 | 167 |
| 1999 | 0.15 | 157 |
| 1998 | -.27 | 173 |
| 1997 | 0.03 | 163 |
| 1996 | 0.08 | 158 |
| 1995 | 0.03 | 152 |
| 1994 | 0.06 | 138 |
| 1993 | -.06 | 147 |
| 1992 | -.4 | 146 |
| 1991 | 0.29 | 103 |
| 1990 | 0.01 | 125 |
| 1989 | -.02 | 122 |
| 1988 | 0.02 | 118 |
| 1987 | 0 | 120 |
| 1986 | 0 | 109 |