| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 2.5 | 94 |
| 2015 | 2.8 | 100 |
| 2014 | 5.7 | 42 |
| 2013 | 5.2 | 55 |
| 2012 | 1.89 | 127 |
| 2011 | 4.85 | 79 |
| 2010 | 6.87 | 49 |
| 2009 | 8.33 | 13 |
| 2008 | 7.64 | 34 |
| 2007 | 9.6 | 29 |
| 2006 | 4.7 | 126 |
| 2005 | 3.27 | 140 |
| 2004 | 5.42 | 88 |
| 2003 | 5.71 | 67 |
| 2002 | 1.7 | 134 |
| 2001 | -4.97 | 193 |
| 2000 | 1.58 | 159 |
| 1999 | 3.04 | 110 |
| 1998 | 3.9 | 95 |
| 1997 | 3.79 | 111 |
| 1996 | 7.32 | 35 |
| 1995 | 16.73 | 4 |
| 1994 | -10.24 | 172 |
| 1993 | 9.69 | 11 |
| 1992 | -7.33 | 160 |
| 1991 | 8.73 | 15 |
| 1990 | 5.69 | 43 |
| 1989 | 1.34 | 120 |
| 1988 | 3.18 | 106 |
| 1987 | 1.63 | 115 |
| 1986 | -.21 | 134 |