| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 5.84 | 90 |
| 2015 | 4.22 | 112 |
| 2014 | -43.99 | 153 |
| 2013 | 8.49 | 90 |
| 2012 | 6.5 | 108 |
| 2011 | 11.48 | 77 |
| 2010 | 3.04 | 140 |
| 2009 | 5.82 | 111 |
| 2008 | 13.25 | 95 |
| 2007 | 57.82 | 6 |
| 2006 | 6.94 | 147 |
| 2005 | 10.03 | 114 |
| 2004 | 7.23 | 126 |
| 2003 | -.07 | 148 |
| 2002 | 11.04 | 84 |
| 2001 | 8.61 | 110 |
| 2000 | 8.02 | 115 |
| 1999 | 15.54 | 66 |
| 1998 | 19.65 | 34 |
| 1997 | 14.95 | 87 |
| 1996 | 24.98 | 45 |
| 1995 | 21.67 | 56 |
| 1994 | 24.59 | 62 |
| 1993 | 21.97 | 58 |
| 1992 | 26.47 | 40 |
| 1991 | 17.73 | 61 |
| 1990 | 19.42 | 51 |
| 1989 | 21.07 | 45 |
| 1988 | 22.25 | 44 |
| 1987 | 27.24 | 35 |
| 1986 | 20.75 | 40 |