| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 7.52 | 19 |
| 2015 | 9.54 | 16 |
| 2014 | 3.03 | 66 |
| 2013 | 2.08 | 81 |
| 2012 | 1.88 | 96 |
| 2011 | 5 | 47 |
| 2010 | 10.57 | 19 |
| 2009 | -.23 | 133 |
| 2008 | 7.46 | 40 |
| 2007 | 4.52 | 72 |
| 2006 | 2.68 | 95 |
| 2005 | 4.15 | 58 |
| 2004 | 1.92 | 91 |
| 2003 | 0.43 | 113 |
| 2002 | 9.1 | 25 |
| 2001 | 8.05 | 28 |
| 2000 | 1.79 | 84 |
| 1999 | 1.49 | 93 |
| 1998 | 4.72 | 38 |
| 1997 | -.64 | 108 |
| 1996 | 1.97 | 79 |
| 1995 | 4.64 | 35 |
| 1994 | -.43 | 85 |
| 1993 | 2.76 | 53 |
| 1992 | -7.95 | 101 |
| 1991 | 8.68 | 21 |
| 1990 | 0.95 | 63 |
| 1989 | -7.05 | 92 |
| 1988 | -18.54 | 95 |
| 1987 | 6.65 | 23 |
| 1986 | 6.62 | 25 |