| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 5.588 | 99 |
| 2015 | 5.515 | 105 |
| 2014 | 8.098 | 90 |
| 2013 | 9.262 | 80 |
| 2012 | 10.057 | 73 |
| 2011 | 9.03 | 85 |
| 2010 | 4.755 | 144 |
| 2009 | 7.251 | 114 |
| 2008 | 13.262 | 59 |
| 2007 | 8.671 | 107 |
| 2006 | 7.999 | 114 |
| 2005 | 6.678 | 127 |
| 2004 | 5.127 | 145 |
| 2003 | 6.179 | 127 |
| 2002 | 7.758 | 117 |
| 2001 | 11.891 | 88 |
| 2000 | 14.843 | 74 |
| 1999 | 12.623 | 91 |
| 1998 | 20.17 | 55 |
| 1997 | 15.67 | 72 |
| 1996 | 17.368 | 68 |
| 1995 | 18.16 | 55 |
| 1994 | 20.34 | 40 |
| 1993 | 24.346 | 38 |
| 1992 | 23.971 | 28 |
| 1991 | 28.575 | 22 |
| 1990 | 48.869 | 5 |
| 1989 | 36.009 | 9 |
| 1988 | 21.213 | 20 |
| 1987 | 32.666 | 7 |
| 1986 | 26.359 | 9 |