| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 2.5 | 74 |
| 2015 | 1.74 | 107 |
| 2014 | 0.86 | 145 |
| 2013 | 0.7 | 151 |
| 2012 | 0.66 | 152 |
| 2011 | 0.8 | 144 |
| 2010 | 0.98 | 144 |
| 2009 | 1.46 | 121 |
| 2008 | 2.49 | 80 |
| 2007 | 3.34 | 59 |
| 2006 | 3.15 | 66 |
| 2005 | 2.63 | 79 |
| 2004 | 2.29 | 88 |
| 2003 | 2.09 | 99 |
| 2002 | 2.11 | 101 |
| 2001 | 2.01 | 105 |
| 2000 | 1.76 | 112 |
| 1999 | 1.55 | 119 |
| 1998 | 1.47 | 125 |
| 1997 | 1.43 | 127 |
| 1996 | 1.18 | 144 |
| 1995 | 0.89 | 148 |
| 1994 | 0.77 | 158 |
| 1993 | 0.88 | 157 |
| 1992 | 1.07 | 149 |
| 1991 | 0.82 | 164 |
| 1990 | 0.3 | 187 |
| 1989 | -.18 | 198 |
| 1988 | -.22 | 199 |
| 1987 | 0.22 | 192 |
| 1986 | 0.31 | 189 |