| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 0.58 | 84 |
| 2015 | 1.1 | 102 |
| 2014 | 0.31 | 141 |
| 2013 | 1.37 | 136 |
| 2012 | 2.42 | 135 |
| 2011 | 2.72 | 153 |
| 2010 | 1.52 | 139 |
| 2009 | 2.09 | 110 |
| 2008 | 4.26 | 149 |
| 2007 | 1.25 | 163 |
| 2006 | 2.77 | 124 |
| 2005 | 3.01 | 116 |
| 2004 | 2.79 | 105 |
| 2003 | 1.3 | 134 |
| 2002 | 2.19 | 110 |
| 2001 | 2.93 | 109 |
| 2000 | 2.37 | 110 |
| 1999 | 2.13 | 106 |
| 1998 | 2.39 | 113 |
| 1997 | 3.11 | 109 |
| 1996 | 2.05 | 135 |
| 1995 | 4.43 | 116 |
| 1994 | 4.13 | 110 |
| 1993 | 4.14 | 100 |
| 1992 | 1.63 | 124 |
| 1991 | 2.54 | 121 |
| 1990 | 2.98 | 116 |
| 1989 | 0.85 | 123 |
| 1988 | 0.94 | 117 |
| 1987 | 0.43 | 111 |
| 1986 | 2.03 | 92 |