| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 5.6 | 31 |
| 2015 | 11.26 | 9 |
| 2014 | 10.34 | 14 |
| 2013 | 9.53 | 24 |
| 2012 | 4.05 | 64 |
| 2011 | 12.05 | 23 |
| 2010 | 9.09 | 40 |
| 2009 | 3.3 | 46 |
| 2008 | 6.53 | 51 |
| 2007 | 11.02 | 24 |
| 2006 | 6.19 | 75 |
| 2005 | 11.17 | 24 |
| 2004 | 10.89 | 33 |
| 2003 | 10.94 | 31 |
| 2002 | 9.37 | 25 |
| 2001 | 6.6 | 38 |
| 2000 | 4.52 | 78 |
| 1999 | 6.73 | 40 |
| 1998 | 10.29 | 19 |
| 1997 | 6.68 | 48 |
| 1996 | 6.68 | 42 |
| 1995 | -1.92 | 112 |
| 1994 | 1.62 | 94 |
| 1993 | -3.86 | 99 |
| 1992 | 0.04 | 80 |
| 1991 | 0.17 | 80 |