| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 0.66 | 164 |
| 2015 | 0.6 | 166 |
| 2014 | 0.56 | 163 |
| 2013 | 0.58 | 159 |
| 2012 | 0.69 | 151 |
| 2011 | 0.88 | 141 |
| 2010 | 1.1 | 135 |
| 2009 | 1.3 | 127 |
| 2008 | 1.45 | 122 |
| 2007 | 1.52 | 120 |
| 2006 | 1.51 | 123 |
| 2005 | 1.48 | 126 |
| 2004 | 1.47 | 124 |
| 2003 | 1.48 | 124 |
| 2002 | 1.61 | 124 |
| 2001 | 1.96 | 107 |
| 2000 | 2.02 | 99 |
| 1999 | 2.07 | 98 |
| 1998 | 2.12 | 98 |
| 1997 | 2.19 | 98 |
| 1996 | 2.27 | 96 |
| 1995 | 2.34 | 99 |
| 1994 | 2.4 | 98 |
| 1993 | 2.53 | 97 |
| 1992 | 2.82 | 86 |
| 1991 | 2.75 | 99 |
| 1990 | 2.68 | 98 |
| 1989 | 2.59 | 110 |
| 1988 | 2.43 | 115 |
| 1987 | 2.18 | 128 |
| 1986 | 1.88 | 137 |