| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 3.92 | 60 |
| 2015 | 1.07 | 153 |
| 2014 | 0.61 | 166 |
| 2013 | 0.8 | 161 |
| 2012 | 1.08 | 144 |
| 2011 | 3.97 | 97 |
| 2010 | 1.47 | 160 |
| 2009 | -1.27 | 119 |
| 2008 | 6.65 | 50 |
| 2007 | 15.17 | 6 |
| 2006 | 7.98 | 48 |
| 2005 | 6.91 | 56 |
| 2004 | 10.2 | 22 |
| 2003 | 4.18 | 97 |
| 2002 | 5.25 | 49 |
| 2001 | 2.23 | 120 |
| 2000 | 14.28 | 4 |
| 1999 | 11.22 | 9 |
| 1998 | 12.52 | 8 |
| 1997 | 11.12 | 11 |
| 1996 | 11.35 | 9 |
| 1995 | 14.21 | 5 |
| 1994 | 19.18 | 2 |
| 1993 | 8.71 | 16 |
| 1992 | 10.94 | 12 |
| 1991 | 1.4 | 103 |
| 1990 | 0.69 | 116 |
| 1989 | 5.7 | 45 |
| 1988 | 6 | 54 |
| 1987 | 4.31 | 64 |
| 1986 | 2.87 | 90 |