| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 2.79 | 67 |
| 2015 | 3.33 | 68 |
| 2014 | 4.37 | 52 |
| 2013 | 2.46 | 100 |
| 2012 | 3.01 | 75 |
| 2011 | 4.46 | 71 |
| 2010 | 6.15 | 41 |
| 2009 | 3.47 | 68 |
| 2008 | 4.49 | 78 |
| 2007 | 6.69 | 38 |
| 2006 | 5.55 | 45 |
| 2005 | 4.38 | 57 |
| 2004 | 4.97 | 63 |
| 2003 | 3.98 | 61 |
| 2002 | -.12 | 116 |
| 2001 | 2.76 | 76 |
| 2000 | 7.39 | 26 |
| 1999 | 3.88 | 72 |
| 1998 | 3.94 | 54 |
| 1997 | 4.52 | 43 |
| 1996 | 2.97 | 83 |
| 1995 | -.37 | 98 |
| 1994 | 0.74 | 77 |
| 1993 | 2.39 | 58 |
| 1992 | 2.32 | 63 |
| 1991 | 2.13 | 65 |
| 1990 | 9.21 | 18 |
| 1989 | -.18 | 78 |
| 1988 | -.44 | 81 |
| 1987 | 0.1 | 70 |
| 1986 | 3.33 | 48 |