| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 41.3 | 32 |
| 2015 | 41.6 | 31 |
| 2014 | 42 | 31 |
| 2013 | 42.4 | 29 |
| 2012 | 42.8 | 29 |
| 2011 | 43.2 | 27 |
| 2010 | 43.5 | 23 |
| 2009 | 43.8 | 23 |
| 2008 | 44.1 | 20 |
| 2007 | 44.3 | 20 |
| 2006 | 44.5 | 20 |
| 2005 | 44.7 | 20 |
| 2004 | 44.9 | 20 |
| 2003 | 45 | 20 |
| 2002 | 45.1 | 19 |
| 2001 | 45.2 | 18 |
| 2000 | 45.2 | 19 |
| 1999 | 45.2 | 25 |
| 1998 | 45.2 | 27 |
| 1997 | 45.2 | 28 |
| 1996 | 45.2 | 29 |
| 1995 | 45.2 | 31 |
| 1994 | 45.3 | 30 |
| 1993 | 45.4 | 34 |
| 1992 | 45.5 | 33 |
| 1991 | 45.5 | 35 |
| 1990 | 45.6 | 36 |
| 1989 | 45.7 | 38 |
| 1988 | 45.8 | 36 |
| 1987 | 45.9 | 35 |
| 1986 | 46 | 32 |