| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 2.32 | 61 |
| 2015 | 2.08 | 85 |
| 2014 | 2.66 | 74 |
| 2013 | 0.98 | 107 |
| 2012 | 1.56 | 101 |
| 2011 | 0.97 | 101 |
| 2010 | 2.17 | 81 |
| 2009 | 4.12 | 81 |
| 2008 | 2.42 | 105 |
| 2007 | 2.04 | 103 |
| 2006 | 1.94 | 105 |
| 2005 | 1.85 | 100 |
| 2004 | 1.32 | 103 |
| 2003 | 1.3 | 99 |
| 2002 | 2.87 | 82 |
| 2001 | 4.1 | 64 |
| 2000 | 2.06 | 81 |
| 1999 | 3.15 | 63 |
| 1998 | 3.56 | 55 |
| 1997 | 2.94 | 60 |
| 1996 | 2.82 | 60 |
| 1995 | 1.01 | 72 |
| 1994 | 1.44 | 63 |
| 1993 | 3.63 | 46 |
| 1992 | 6.06 | 26 |
| 1991 | 5.83 | 34 |
| 1990 | 4.48 | 33 |
| 1989 | 3.12 | 48 |
| 1988 | -.99 | 76 |
| 1987 | 4.26 | 36 |
| 1986 | 2.21 | 55 |