| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 4.9 | 17 |
| 2015 | 7.62 | 3 |
| 2014 | 7.45 | 3 |
| 2013 | 7.73 | 10 |
| 2012 | 5.83 | 22 |
| 2011 | 8.28 | 15 |
| 2010 | 9.62 | 8 |
| 2009 | 5.96 | 11 |
| 2008 | 7.88 | 16 |
| 2007 | 8.5 | 28 |
| 2006 | 7.85 | 30 |
| 2005 | 8.75 | 18 |
| 2004 | 10.41 | 12 |
| 2003 | -4.92 | 192 |
| 2002 | -1.37 | 161 |
| 2001 | 5.21 | 31 |
| 2000 | 3.05 | 97 |
| 1999 | 2.16 | 89 |
| 1998 | -6.25 | 186 |
| 1997 | 0.05 | 155 |
| 1996 | 8.92 | 10 |
| 1995 | 2.65 | 80 |
| 1994 | -.34 | 132 |
| 1993 | 9.16 | 8 |
| 1992 | -11.9 | 165 |
| 1991 | -10.37 | 165 |
| 1990 | -.75 | 110 |
| 1989 | -3.64 | 140 |
| 1988 | -2.71 | 142 |
| 1987 | 10.27 | 6 |
| 1986 | 6.22 | 23 |