| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 8.655 | 64 |
| 2015 | 8.963 | 71 |
| 2014 | 9.186 | 73 |
| 2013 | 9.27 | 79 |
| 2012 | 9.726 | 77 |
| 2011 | 10.686 | 66 |
| 2010 | 10.575 | 69 |
| 2009 | 10.993 | 79 |
| 2008 | 9.529 | 92 |
| 2007 | 9.756 | 96 |
| 2006 | 9.852 | 92 |
| 2005 | 10.065 | 90 |
| 2004 | 10.185 | 90 |
| 2003 | 12.048 | 79 |
| 2002 | 11.309 | 92 |
| 2001 | 10.187 | 102 |
| 2000 | 11.599 | 96 |
| 1999 | 11.621 | 100 |
| 1998 | 11.732 | 100 |
| 1997 | 11.236 | 99 |
| 1996 | 9.992 | 111 |
| 1995 | 11.075 | 99 |
| 1994 | 11.028 | 85 |
| 1993 | 11.832 | 81 |
| 1992 | 12.023 | 78 |
| 1991 | 12.302 | 70 |
| 1990 | 10.5 | 79 |
| 1989 | 10.5 | 79 |
| 1988 | 10.5 | 67 |
| 1987 | 11.333 | 62 |
| 1986 | 11.5 | 62 |