| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 1.2 | 140 |
| 2015 | 5.3 | 35 |
| 2014 | 6.46 | 25 |
| 2013 | 5.65 | 44 |
| 2012 | 5.06 | 60 |
| 2011 | 5.09 | 73 |
| 2010 | 6.04 | 66 |
| 2009 | 0.3 | 98 |
| 2008 | 2.65 | 127 |
| 2007 | 6.62 | 77 |
| 2006 | 7.07 | 63 |
| 2005 | 2.53 | 161 |
| 2004 | 12.27 | 11 |
| 2003 | 4.24 | 94 |
| 2002 | 4.79 | 56 |
| 2001 | 1.18 | 153 |
| 2000 | 3.49 | 129 |
| 1999 | 3.37 | 98 |
| 1998 | 3.29 | 116 |
| 1997 | 4.22 | 102 |
| 1996 | 3.19 | 118 |
| 1995 | 3.9 | 101 |
| 1994 | 1.73 | 130 |
| 1993 | -1.58 | 151 |
| 1992 | 7.19 | 32 |
| 1991 | 8.17 | 20 |
| 1990 | 2.05 | 101 |
| 1989 | 1.86 | 114 |
| 1988 | 0.81 | 132 |
| 1987 | 3.55 | 78 |
| 1986 | 4.77 | 59 |