| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 3.65 | 28 |
| 2015 | 2.59 | 67 |
| 2014 | 2.51 | 79 |
| 2013 | 2.21 | 87 |
| 2012 | 1.34 | 115 |
| 2011 | 0.61 | 146 |
| 2010 | -.48 | 168 |
| 2009 | 0.74 | 63 |
| 2008 | -.36 | 157 |
| 2007 | 2.72 | 128 |
| 2006 | 4.03 | 96 |
| 2005 | 5.48 | 49 |
| 2004 | 5.18 | 62 |
| 2003 | 2.68 | 97 |
| 2002 | 1.05 | 123 |
| 2001 | -.23 | 152 |
| 2000 | 1.91 | 128 |
| 1999 | 1.25 | 115 |
| 1998 | 0.1 | 147 |
| 1997 | -1.45 | 168 |
| 1996 | 2.26 | 107 |
| 1995 | 2.35 | 92 |
| 1994 | 1.12 | 105 |
| 1993 | -.86 | 112 |
| 1992 | 4.85 | 36 |
| 1991 | 2.17 | 58 |
| 1990 | 1.46 | 80 |
| 1989 | 1.84 | 81 |
| 1988 | 4.32 | 54 |
| 1987 | 3.1 | 55 |
| 1986 | 2.13 | 76 |