| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 14.77 | 44 |
| 2015 | 15.51 | 49 |
| 2014 | 16.11 | 51 |
| 2013 | 16.28 | 52 |
| 2012 | 17.09 | 50 |
| 2011 | 17.71 | 48 |
| 2010 | 17.81 | 49 |
| 2009 | 17.87 | 48 |
| 2008 | 18.47 | 47 |
| 2007 | 18.71 | 52 |
| 2006 | 19.01 | 51 |
| 2005 | 19.6 | 49 |
| 2004 | 20.31 | 51 |
| 2003 | 20.92 | 48 |
| 2002 | 21.67 | 47 |
| 2001 | 23 | 44 |
| 2000 | 23.77 | 43 |
| 1999 | 23.79 | 48 |
| 1998 | 23.76 | 48 |
| 1997 | 24.46 | 43 |
| 1996 | 24.47 | 45 |
| 1995 | 26.38 | 42 |
| 1994 | 25.63 | 41 |
| 1993 | 26.25 | 43 |
| 1992 | 29.38 | 35 |
| 1991 | 30.37 | 35 |
| 1990 | 32.75 | 27 |
| 1989 | 32.93 | 22 |
| 1988 | 33.55 | 22 |
| 1987 | 34.77 | 18 |
| 1986 | 34.13 | 21 |