| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 4.76 | 95 |
| 2015 | 13.94 | 43 |
| 2014 | 10.4 | 73 |
| 2013 | 18.99 | 27 |
| 2012 | 5.9 | 114 |
| 2011 | 11.46 | 78 |
| 2010 | 3.51 | 136 |
| 2009 | 7.08 | 106 |
| 2008 | -6.47 | 163 |
| 2007 | 8.29 | 142 |
| 2006 | 22.27 | 62 |
| 2005 | 15.17 | 81 |
| 2004 | 9.46 | 111 |
| 2003 | 16.28 | 61 |
| 2002 | 21.07 | 44 |
| 2001 | 11.51 | 92 |
| 2000 | -1.55 | 151 |
| 1999 | 13.64 | 78 |
| 1998 | -.54 | 138 |
| 1997 | -8.73 | 152 |
| 1996 | 0.86 | 145 |
| 1995 | 4.49 | 128 |
| 1994 | 2.54 | 138 |
| 1993 | 6.34 | 99 |
| 1992 | 14.57 | 73 |
| 1991 | 14.55 | 74 |
| 1990 | 25.69 | 37 |
| 1989 | 8.72 | 93 |
| 1988 | 20.42 | 54 |
| 1987 | 4.24 | 99 |
| 1986 | 17.37 | 53 |