| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 0.78 | 87 |
| 2015 | 1.97 | 88 |
| 2014 | -.33 | 119 |
| 2013 | -2.11 | 139 |
| 2012 | -4.7 | 148 |
| 2011 | -.29 | 115 |
| 2010 | 1.51 | 95 |
| 2009 | 4.13 | 80 |
| 2008 | 5.93 | 51 |
| 2007 | 6.18 | 55 |
| 2006 | 4.97 | 69 |
| 2005 | 5.63 | 48 |
| 2004 | 6.34 | 36 |
| 2003 | 4.92 | 45 |
| 2002 | 3.89 | 63 |
| 2001 | 3.8 | 70 |
| 2000 | 4.38 | 47 |
| 1999 | 3.87 | 49 |
| 1998 | 3.39 | 58 |
| 1997 | 2.68 | 68 |
| 1996 | 1.22 | 88 |
| 1995 | 2.43 | 60 |
| 1994 | 0.54 | 75 |
| 1993 | 2.66 | 54 |
| 1992 | 3.49 | 40 |
| 1991 | 6.04 | 31 |
| 1990 | 6.27 | 19 |
| 1989 | 8.33 | 19 |
| 1988 | 3.65 | 40 |
| 1987 | 9.17 | 14 |
| 1986 | 4.65 | 35 |