| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 13.65 | 47 |
| 2015 | 13.24 | 59 |
| 2014 | 12.99 | 60 |
| 2013 | 13.28 | 61 |
| 2012 | 12.92 | 60 |
| 2011 | 12.51 | 61 |
| 2010 | 12.85 | 61 |
| 2009 | 13.83 | 57 |
| 2008 | 13.47 | 56 |
| 2007 | 12.88 | 62 |
| 2006 | 13.88 | 63 |
| 2005 | 14.38 | 62 |
| 2004 | 15.37 | 60 |
| 2003 | 15.42 | 61 |
| 2002 | 14.9 | 65 |
| 2001 | 15.22 | 65 |
| 2000 | 15.01 | 68 |
| 1999 | 15.11 | 70 |
| 1998 | 14.67 | 72 |
| 1997 | 17.24 | 66 |
| 1996 | 16.38 | 72 |
| 1995 | 16.88 | 67 |
| 1994 | 17.11 | 65 |
| 1993 | 16.33 | 69 |
| 1992 | 16.03 | 68 |
| 1991 | 17.09 | 66 |
| 1990 | 16.74 | 70 |
| 1989 | 16.67 | 60 |
| 1988 | 17.16 | 59 |
| 1987 | 17.72 | 57 |
| 1986 | 18.33 | 54 |