| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 3.03 | 62 |
| 2015 | 4.57 | 49 |
| 2014 | 2.36 | 97 |
| 2013 | 2.4 | 101 |
| 2012 | 2.25 | 94 |
| 2011 | 2.41 | 110 |
| 2010 | 0.85 | 92 |
| 2009 | 2.66 | 86 |
| 2008 | 0.71 | 124 |
| 2007 | 0.81 | 120 |
| 2006 | 2.53 | 93 |
| 2005 | 1.07 | 103 |
| 2004 | 2.15 | 108 |
| 2003 | 2.21 | 95 |
| 2002 | 2.83 | 79 |
| 2001 | 5.3 | 50 |
| 2000 | 5.38 | 48 |
| 1999 | 1.57 | 103 |
| 1998 | 2.44 | 76 |
| 1997 | 4.02 | 55 |
| 1996 | 2.05 | 96 |
| 1995 | 1.51 | 84 |
| 1994 | 0.28 | 82 |
| 1993 | -.17 | 83 |
| 1992 | 0.58 | 77 |
| 1991 | -.81 | 85 |
| 1990 | 5.25 | 44 |
| 1989 | 5.67 | 31 |
| 1988 | 7.73 | 30 |
| 1987 | 4.6 | 37 |
| 1986 | 5.02 | 32 |