| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 11.8 | 42 |
| 2015 | 19.31 | 20 |
| 2014 | 11.01 | 65 |
| 2013 | 10.88 | 76 |
| 2012 | 15.55 | 42 |
| 2011 | 14.36 | 60 |
| 2010 | 18.34 | 50 |
| 2009 | 23.14 | 28 |
| 2008 | 26.97 | 28 |
| 2007 | 7.99 | 144 |
| 2006 | 10.29 | 134 |
| 2005 | -2.44 | 162 |
| 2004 | -4.06 | 160 |
| 2003 | 69.08 | 2 |
| 2002 | -3.02 | 152 |
| 2001 | -3.11 | 150 |
| 2000 | 7.51 | 117 |
| 1999 | 2.56 | 145 |
| 1998 | 1.04 | 132 |
| 1997 | 17.73 | 73 |
| 1996 | 5.17 | 133 |
| 1995 | 22.26 | 55 |
| 1994 | 29.39 | 54 |
| 1993 | 7.97 | 93 |
| 1992 | 3.96 | 106 |
| 1991 | 4.47 | 101 |
| 1990 | -.5 | 112 |
| 1989 | 3.74 | 113 |
| 1988 | 16.61 | 65 |
| 1987 | 11.66 | 76 |
| 1986 | 22.36 | 36 |