| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 7.497 | 20 |
| 2015 | 9.148 | 18 |
| 2014 | 9.339 | 19 |
| 2013 | 7.945 | 28 |
| 2012 | 8.408 | 29 |
| 2011 | 5.699 | 55 |
| 2010 | 6.521 | 47 |
| 2009 | 13.297 | 9 |
| 2008 | 11.971 | 12 |
| 2007 | 10.288 | 21 |
| 2006 | 9.743 | 22 |
| 2005 | 10.533 | 18 |
| 2004 | 13.698 | 11 |
| 2003 | 14.218 | 15 |
| 2002 | 16.67 | 14 |
| 2001 | 15.256 | 17 |
| 2000 | 11.691 | 32 |
| 1999 | 12.811 | 32 |
| 1998 | 10.108 | 58 |
| 1997 | 7.169 | 82 |
| 1996 | 13.059 | 50 |
| 1995 | 13.531 | 46 |
| 1994 | 13.092 | 35 |
| 1993 | 23.242 | 22 |
| 1992 | 18.042 | 28 |
| 1991 | 14.917 | 34 |
| 1990 | 19.783 | 24 |
| 1989 | 14.675 | 31 |
| 1988 | 12.95 | 30 |
| 1987 | 13.088 | 26 |
| 1986 | 9.235 | 46 |