| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 3.29 | 44 |
| 2015 | 4.52 | 49 |
| 2014 | 8.21 | 17 |
| 2013 | 7.01 | 31 |
| 2012 | 10.92 | 18 |
| 2011 | 8.85 | 38 |
| 2010 | 7.04 | 38 |
| 2009 | 4.36 | 68 |
| 2008 | 8.33 | 100 |
| 2007 | 5.16 | 90 |
| 2006 | 5 | 84 |
| 2005 | 5.31 | 75 |
| 2004 | -18.11 | 173 |
| 2003 | 1.57 | 128 |
| 2002 | 2.48 | 102 |
| 2001 | 3.41 | 97 |
| 2000 | 4.01 | 74 |
| 1999 | 6.78 | 48 |
| 1998 | 10.58 | 44 |
| 1997 | 6.51 | 75 |
| 1996 | 8.79 | 70 |
| 1995 | 9.5 | 78 |
| 1994 | 6.99 | 94 |
| 1993 | 11.21 | 59 |
| 1992 | 15.98 | 42 |
| 1991 | 12.28 | 58 |
| 1990 | 10 | 61 |
| 1989 | 8.78 | 60 |
| 1988 | 10.08 | 50 |
| 1987 | 6.37 | 66 |
| 1986 | 9.95 | 49 |