| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 3.2 | 41 |
| 2015 | 4.04 | 29 |
| 2014 | 4.27 | 31 |
| 2013 | 4.8 | 28 |
| 2012 | 7.34 | 12 |
| 2011 | 9.86 | 8 |
| 2010 | 3.91 | 72 |
| 2009 | -.19 | 79 |
| 2008 | 6.68 | 27 |
| 2007 | 9.98 | 17 |
| 2006 | 6.68 | 44 |
| 2005 | 5.23 | 53 |
| 2004 | 5.54 | 57 |
| 2003 | 2.26 | 108 |
| 2002 | 0.3 | 135 |
| 2001 | -1.36 | 162 |
| 2000 | 0.71 | 145 |
| 1999 | 1.86 | 96 |
| 1998 | 5.19 | 32 |
| 1997 | 4.31 | 60 |
| 1996 | 1.97 | 114 |
| 1995 | -.31 | 143 |
| 1994 | 0.76 | 111 |
| 1993 | 3.31 | 46 |
| 1992 | 5.98 | 27 |
| 1991 | 7.16 | 13 |
| 1990 | 5.85 | 21 |
| 1989 | -.57 | 123 |
| 1988 | -15.22 | 163 |
| 1987 | -3.92 | 140 |
| 1986 | 1.32 | 93 |