| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 14.3 | 45 |
| 2015 | 13.89 | 47 |
| 2014 | 13.59 | 46 |
| 2013 | 13.36 | 45 |
| 2012 | 13.19 | 44 |
| 2011 | 13.06 | 45 |
| 2010 | 12.97 | 45 |
| 2009 | 12.96 | 39 |
| 2008 | 13.01 | 39 |
| 2007 | 13.07 | 38 |
| 2006 | 13.11 | 38 |
| 2005 | 13.06 | 38 |
| 2004 | 12.88 | 38 |
| 2003 | 12.61 | 39 |
| 2002 | 12.28 | 38 |
| 2001 | 11.93 | 39 |
| 2000 | 11.57 | 41 |
| 1999 | 11.21 | 43 |
| 1998 | 10.85 | 44 |
| 1997 | 10.49 | 45 |
| 1996 | 10.14 | 46 |
| 1995 | 9.8 | 47 |
| 1994 | 9.42 | 49 |
| 1993 | 9.08 | 49 |
| 1992 | 8.77 | 50 |
| 1991 | 8.49 | 50 |
| 1990 | 8.24 | 51 |
| 1989 | 8.07 | 50 |
| 1988 | 7.93 | 50 |
| 1987 | 7.82 | 49 |
| 1986 | 7.75 | 48 |