| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 2.1 | 77 |
| 2015 | 6.4 | 30 |
| 2014 | 2.5 | 92 |
| 2013 | 8.2 | 27 |
| 2012 | 7.2 | 28 |
| 2011 | 11.6 | 17 |
| 2010 | 4.9 | 52 |
| 2009 | 21.11 | 5 |
| 2008 | -3.8 | 151 |
| 2007 | 2.5 | 93 |
| 2006 | 8.1 | 25 |
| 2005 | 2.28 | 82 |
| 2004 | 5.35 | 59 |
| 2003 | 19.46 | 5 |
| 2002 | -1.24 | 125 |
| 2001 | 12.78 | 13 |
| 2000 | -4.64 | 136 |
| 1999 | 2.7 | 87 |
| 1998 | 11.4 | 14 |
| 1997 | -13.45 | 152 |
| 1996 | 23.9 | 5 |
| 1995 | 14.96 | 10 |
| 1994 | -9 | 116 |
| 1993 | -3.7 | 98 |
| 1992 | 4.6 | 45 |
| 1991 | 15.4 | 6 |
| 1990 | -6.2 | 98 |
| 1989 | 15.3 | 4 |
| 1988 | -6.8 | 105 |
| 1987 | 17.1 | 8 |
| 1986 | -1.3 | 83 |