| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 3.3 | 72 |
| 2015 | 2.92 | 95 |
| 2014 | 4.7 | 57 |
| 2013 | 5.06 | 56 |
| 2012 | 7.6 | 23 |
| 2011 | 5.56 | 64 |
| 2010 | 10.3 | 12 |
| 2009 | 9.22 | 8 |
| 2008 | 7.77 | 33 |
| 2007 | 8.35 | 48 |
| 2006 | 7.9 | 49 |
| 2005 | 7.24 | 50 |
| 2004 | 7.03 | 53 |
| 2003 | 6.94 | 46 |
| 2002 | 4.51 | 63 |
| 2001 | 5.32 | 44 |
| 2000 | 3.9 | 110 |
| 1999 | 4.65 | 58 |
| 1998 | -.39 | 168 |
| 1997 | 3.81 | 110 |
| 1996 | 6.22 | 51 |
| 1995 | 2.9 | 114 |
| 1994 | -8.63 | 171 |
| 1993 | 6.8 | 31 |
| 1992 | -1.73 | 138 |
| 1991 | -.04 | 121 |
| 1990 | -.48 | 129 |
| 1989 | -1.02 | 143 |
| 1988 | 6.28 | 52 |
| 1987 | 2.68 | 94 |
| 1986 | 0.72 | 123 |