| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2015 | 0.36 | 167 |
| 2014 | 0.76 | 159 |
| 2013 | 0.58 | 162 |
| 2012 | 0.38 | 171 |
| 2011 | 0.62 | 167 |
| 2010 | 1.14 | 149 |
| 2009 | 1.39 | 138 |
| 2008 | 3.2 | 118 |
| 2007 | 3.67 | 117 |
| 2006 | 3.11 | 120 |
| 2005 | 2.01 | 123 |
| 2004 | 1.14 | 140 |
| 2003 | 0.64 | 152 |
| 2002 | 1.14 | 126 |
| 2001 | 0.52 | 144 |
| 2000 | 0.42 | 150 |
| 1999 | 0.84 | 127 |
| 1998 | 0.81 | 134 |
| 1997 | 1.15 | 122 |
| 1996 | 1.46 | 86 |
| 1995 | 1.19 | 89 |
| 1994 | 0.81 | 99 |
| 1993 | 0.68 | 97 |
| 1992 | 0.69 | 80 |
| 1991 | 0.57 | 83 |
| 1990 | 0.61 | 86 |
| 1989 | 0.52 | 75 |
| 1988 | 0.48 | 76 |
| 1987 | 0.39 | 84 |
| 1986 | 0.33 | 78 |