| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2013 | 2.61 | 94 |
| 2012 | 6.06 | 56 |
| 2011 | 15.52 | 14 |
| 2010 | 2.8 | 109 |
| 2009 | 2.46 | 101 |
| 2008 | 10.36 | 71 |
| 2007 | 6.25 | 73 |
| 2006 | 1.46 | 164 |
| 2005 | 2.65 | 123 |
| 2004 | -2.2 | 170 |
| 2003 | -2.19 | 171 |
| 2002 | -9.8 | 171 |
| 2001 | -8.81 | 169 |
| 2000 | -2.9 | 164 |
| 1999 | 2.65 | 90 |
| 1998 | 3.71 | 96 |
| 1997 | 3.55 | 104 |
| 1996 | 4.03 | 107 |
| 1995 | 7.24 | 98 |
| 1994 | 5.11 | 104 |
| 1993 | 11.07 | 60 |
| 1992 | 9.36 | 66 |
| 1991 | 11.9 | 60 |
| 1990 | 8.45 | 68 |
| 1989 | 1.51 | 116 |
| 1988 | 6.09 | 75 |
| 1987 | 4.36 | 76 |
| 1986 | 3.29 | 82 |