| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 2.7 | 56 |
| 2015 | 3.27 | 50 |
| 2014 | 3.84 | 41 |
| 2013 | 5.14 | 21 |
| 2012 | 3.47 | 54 |
| 2011 | 3.53 | 70 |
| 2010 | 2.45 | 103 |
| 2009 | 1.67 | 44 |
| 2008 | 4.4 | 61 |
| 2007 | 2.81 | 125 |
| 2006 | 3.01 | 119 |
| 2005 | 2.62 | 117 |
| 2004 | 2.35 | 128 |
| 2003 | 0.88 | 142 |
| 2002 | 0.63 | 130 |
| 2001 | -.19 | 151 |
| 2000 | 0.58 | 152 |
| 1999 | -1.49 | 157 |
| 1998 | 3 | 83 |
| 1997 | 2.91 | 89 |
| 1996 | 2.32 | 100 |
| 1995 | 2.63 | 83 |
| 1994 | 2.62 | 76 |
| 1993 | 2.23 | 68 |
| 1992 | -.34 | 100 |
| 1991 | 3.21 | 41 |
| 1990 | 2.6 | 64 |
| 1989 | 1.78 | 82 |
| 1988 | 0.91 | 105 |
| 1987 | 0.45 | 98 |
| 1986 | -4.52 | 145 |