| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 5.04 | 31 |
| 2015 | 7.43 | 8 |
| 2014 | 8.31 | 7 |
| 2013 | 4.51 | 72 |
| 2012 | 2.58 | 113 |
| 2011 | 1.4 | 157 |
| 2010 | 3.54 | 111 |
| 2009 | -2.46 | 135 |
| 2008 | 3.35 | 109 |
| 2007 | 3.99 | 132 |
| 2006 | 1.83 | 181 |
| 2005 | 3.78 | 125 |
| 2004 | 0.44 | 192 |
| 2003 | 2.54 | 135 |
| 2002 | 2.98 | 110 |
| 2001 | 0.61 | 161 |
| 2000 | 6.77 | 34 |
| 1999 | 4.72 | 54 |
| 1998 | 5.13 | 53 |
| 1997 | 5.26 | 73 |
| 1996 | 3.78 | 109 |
| 1995 | 6.34 | 49 |
| 1994 | 5.65 | 51 |
| 1993 | 4.48 | 61 |
| 1992 | 4.69 | 56 |
| 1991 | 6.26 | 34 |
| 1990 | 6.29 | 36 |
| 1989 | 8.18 | 21 |
| 1988 | 8.41 | 31 |
| 1987 | 4.11 | 65 |
| 1986 | 3.89 | 74 |