| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 5.82 | 29 |
| 2015 | 7.26 | 31 |
| 2014 | 6.08 | 47 |
| 2013 | 5.33 | 56 |
| 2012 | 4.18 | 60 |
| 2011 | 7.25 | 50 |
| 2010 | 8.68 | 43 |
| 2009 | 3.7 | 42 |
| 2008 | -.05 | 124 |
| 2007 | 6.13 | 79 |
| 2006 | 5.89 | 80 |
| 2005 | 4.39 | 84 |
| 2004 | 4.07 | 96 |
| 2003 | 6.12 | 65 |
| 2002 | 2.35 | 102 |
| 2001 | 5.5 | 43 |
| 2000 | -1.83 | 141 |
| 1999 | -2.36 | 137 |
| 1998 | 0.24 | 120 |
| 1997 | 1.19 | 114 |
| 1996 | 3.4 | 83 |
| 1995 | 3.53 | 74 |
| 1994 | 1.9 | 93 |
| 1993 | 0.2 | 74 |
| 1992 | -.05 | 82 |
| 1991 | 2.53 | 60 |
| 1990 | 4.67 | 41 |
| 1989 | 6.18 | 43 |
| 1988 | 5.36 | 49 |
| 1987 | 5.29 | 44 |
| 1986 | 3.98 | 56 |