| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2015 | 6.31 | 49 |
| 2014 | 1.2 | 145 |
| 2013 | 4.5 | 57 |
| 2012 | 3.14 | 94 |
| 2011 | 19.38 | 9 |
| 2010 | 3.94 | 74 |
| 2009 | 1.46 | 135 |
| 2008 | 1.6 | 150 |
| 2007 | 2.47 | 140 |
| 2006 | 4.15 | 99 |
| 2005 | 4.54 | 74 |
| 2004 | 4.12 | 67 |
| 2003 | 2.73 | 84 |
| 2002 | 3.9 | 62 |
| 2001 | 5.45 | 37 |
| 2000 | 4.07 | 67 |
| 1999 | 2.7 | 88 |
| 1998 | 1.9 | 106 |
| 1997 | 1.4 | 113 |
| 1996 | 1.18 | 98 |
| 1995 | 2 | 66 |
| 1994 | 1.57 | 62 |
| 1993 | -.96 | 151 |
| 1992 | -.77 | 151 |
| 1991 | 0.4 | 94 |
| 1990 | 1.12 | 61 |
| 1989 | 0.68 | 68 |
| 1988 | 0.94 | 51 |
| 1987 | 0.57 | 72 |
| 1986 | 0.58 | 60 |