| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2015 | 9.45 | 17 |
| 2014 | 4.78 | 41 |
| 2013 | 4.69 | 53 |
| 2012 | 3.26 | 74 |
| 2011 | 6.67 | 36 |
| 2010 | 1.01 | 107 |
| 2009 | 3.84 | 83 |
| 2008 | 10.24 | 27 |
| 2007 | 19.06 | 12 |
| 2006 | 10.98 | 20 |
| 2005 | -5.92 | 140 |
| 2004 | 4.97 | 45 |
| 2003 | 3.14 | 68 |
| 2002 | -2.58 | 127 |
| 2001 | 2.91 | 85 |
| 2000 | 1.27 | 92 |
| 1999 | 4.47 | 41 |
| 1998 | 3.08 | 64 |
| 1997 | 4.04 | 47 |
| 1996 | 2.59 | 69 |
| 1995 | 2.7 | 55 |
| 1994 | 1.58 | 62 |
| 1993 | 0.7 | 74 |
| 1992 | 6.7 | 21 |
| 1991 | 11.78 | 13 |
| 1990 | 6 | 21 |
| 1989 | -2.33 | 85 |
| 1988 | 3.78 | 35 |
| 1987 | 0.24 | 68 |
| 1986 | 2.07 | 58 |