| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 2.5 | 95 |
| 2015 | 5.61 | 32 |
| 2014 | 2.28 | 124 |
| 2013 | 2.15 | 130 |
| 2012 | 5.9 | 42 |
| 2011 | 6.63 | 42 |
| 2010 | 6.54 | 54 |
| 2009 | 2.15 | 73 |
| 2008 | 6.66 | 49 |
| 2007 | 4.81 | 122 |
| 2006 | 4.23 | 135 |
| 2005 | 3.47 | 134 |
| 2004 | 1.69 | 175 |
| 2003 | 4.56 | 85 |
| 2002 | 0.72 | 153 |
| 2001 | 3.56 | 87 |
| 2000 | 3.88 | 111 |
| 1999 | 0.48 | 149 |
| 1998 | 1.54 | 153 |
| 1997 | 3.7 | 114 |
| 1996 | 5.6 | 65 |
| 1995 | 3.29 | 110 |
| 1994 | 5.98 | 43 |
| 1993 | 3.51 | 78 |
| 1992 | 6.96 | 36 |
| 1991 | 6.97 | 28 |
| 1990 | 6.05 | 38 |
| 1989 | 5.8 | 44 |
| 1988 | 8.6 | 27 |
| 1987 | 0.73 | 125 |
| 1986 | 4.68 | 62 |