| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 6.45 | 85 |
| 2015 | 1.52 | 132 |
| 2014 | 11.62 | 60 |
| 2013 | 12.17 | 67 |
| 2012 | 15.25 | 46 |
| 2011 | 5.44 | 122 |
| 2010 | 21.56 | 37 |
| 2009 | 17.08 | 50 |
| 2008 | 33.64 | 16 |
| 2007 | 4.95 | 154 |
| 2006 | 22.66 | 58 |
| 2005 | 24.73 | 41 |
| 2004 | 10.23 | 103 |
| 2003 | 25 | 31 |
| 2002 | 30.19 | 25 |
| 2001 | 14.95 | 78 |
| 2000 | 17.02 | 62 |
| 1999 | 47.59 | 10 |
| 1998 | -.85 | 141 |
| 1997 | 8.44 | 113 |
| 1996 | 18.74 | 63 |
| 1995 | -7.97 | 148 |
| 1994 | 33.04 | 46 |
| 1993 | 5.95 | 105 |
| 1992 | 5.67 | 99 |
| 1991 | 18 | 60 |
| 1990 | 9.99 | 82 |
| 1989 | 18.91 | 53 |
| 1988 | 15.71 | 66 |
| 1987 | 1.69 | 110 |
| 1986 | 0.13 | 113 |