| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 2.13 | 91 |
| 2015 | 1.93 | 100 |
| 2014 | 1.54 | 112 |
| 2013 | 0.8 | 146 |
| 2012 | 0.57 | 161 |
| 2011 | 0.78 | 146 |
| 2010 | 1.13 | 132 |
| 2009 | 1.02 | 141 |
| 2008 | 0.88 | 149 |
| 2007 | 0.96 | 143 |
| 2006 | 1.25 | 135 |
| 2005 | 1.16 | 136 |
| 2004 | 1.52 | 122 |
| 2003 | 2.09 | 100 |
| 2002 | 1.9 | 109 |
| 2001 | 0.69 | 162 |
| 2000 | 0.66 | 161 |
| 1999 | 0.6 | 163 |
| 1998 | 0.96 | 143 |
| 1997 | 1.39 | 130 |
| 1996 | 1.69 | 116 |
| 1995 | 1.58 | 125 |
| 1994 | 1.45 | 129 |
| 1993 | 1.26 | 139 |
| 1992 | 1.16 | 143 |
| 1991 | 5.07 | 27 |
| 1990 | 1.2 | 151 |
| 1989 | 0.76 | 171 |
| 1988 | 0.56 | 184 |
| 1987 | 1.15 | 166 |
| 1986 | 0.1 | 197 |