| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 4.88 | 35 |
| 2015 | 5.78 | 28 |
| 2014 | 6.05 | 31 |
| 2013 | 6.62 | 29 |
| 2012 | 9.23 | 12 |
| 2011 | 11.81 | 9 |
| 2010 | 5.77 | 71 |
| 2009 | 1.6 | 81 |
| 2008 | 8.61 | 22 |
| 2007 | 11.98 | 14 |
| 2006 | 8.65 | 33 |
| 2005 | 7.19 | 51 |
| 2004 | 7.52 | 46 |
| 2003 | 4.21 | 95 |
| 2002 | 2.23 | 125 |
| 2001 | 0.57 | 162 |
| 2000 | 2.72 | 143 |
| 1999 | 3.92 | 77 |
| 1998 | 7.34 | 25 |
| 1997 | 6.46 | 45 |
| 1996 | 4.08 | 102 |
| 1995 | 1.75 | 143 |
| 1994 | 2.85 | 112 |
| 1993 | 5.46 | 47 |
| 1992 | 8.2 | 23 |
| 1991 | 9.42 | 12 |
| 1990 | 8.1 | 19 |
| 1989 | 1.56 | 116 |
| 1988 | -13.38 | 164 |
| 1987 | -1.81 | 146 |
| 1986 | 3.57 | 77 |