| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 2.13 | 55 |
| 2015 | 2.08 | 79 |
| 2014 | 3.17 | 77 |
| 2013 | 2.1 | 107 |
| 2012 | 1.65 | 155 |
| 2011 | 3.2 | 138 |
| 2010 | 1.71 | 134 |
| 2009 | 0.58 | 139 |
| 2008 | 5.44 | 130 |
| 2007 | 2.03 | 151 |
| 2006 | 3.61 | 104 |
| 2005 | 2.96 | 117 |
| 2004 | 1.52 | 132 |
| 2003 | 0.99 | 143 |
| 2002 | 1.81 | 127 |
| 2001 | 1.42 | 143 |
| 2000 | 1.53 | 127 |
| 1999 | 2.74 | 88 |
| 1998 | 5.27 | 81 |
| 1997 | 2.66 | 117 |
| 1996 | 3.49 | 114 |
| 1995 | 3.45 | 120 |
| 1994 | 3.72 | 114 |
| 1993 | 3.54 | 107 |
| 1992 | 4.77 | 89 |
| 1991 | 4.36 | 102 |
| 1990 | 2.62 | 120 |
| 1989 | 2.81 | 110 |
| 1988 | 2.56 | 101 |
| 1987 | 0.29 | 112 |
| 1986 | 0.74 | 110 |