| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 10.83 | 8 |
| 2015 | 9.7 | 21 |
| 2014 | 10.14 | 19 |
| 2013 | 9.52 | 19 |
| 2012 | 8.46 | 34 |
| 2011 | 12.79 | 21 |
| 2010 | 8.82 | 34 |
| 2009 | 4.08 | 73 |
| 2008 | 9.75 | 36 |
| 2007 | 10.61 | 38 |
| 2006 | 16.23 | 22 |
| 2005 | 6.74 | 41 |
| 2004 | 8.51 | 28 |
| 2003 | 7.67 | 27 |
| 2002 | 1.9 | 109 |
| 2001 | 4.85 | 46 |
| 2000 | 6.73 | 34 |
| 1999 | 6.23 | 41 |
| 1998 | 10.39 | 14 |
| 1997 | 12.17 | 9 |
| 1996 | 4.21 | 33 |
| 1995 | 2.33 | 57 |
| 1994 | 4.29 | 22 |
| 1993 | 1.93 | 45 |
| 1992 | 1.8 | 43 |
| 1991 | 1.53 | 44 |
| 1990 | 2.11 | 39 |
| 1989 | 0.87 | 61 |
| 1988 | -10.08 | 136 |
| 1987 | -8.15 | 133 |
| 1986 | 0.3 | 82 |