| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 1.64 | 62 |
| 2015 | 1.56 | 87 |
| 2014 | 0.44 | 137 |
| 2013 | 1.89 | 114 |
| 2012 | 1.28 | 164 |
| 2011 | 0.92 | 171 |
| 2010 | 0.99 | 160 |
| 2009 | 0.99 | 132 |
| 2008 | 3.71 | 157 |
| 2007 | 2.04 | 150 |
| 2006 | 3.28 | 112 |
| 2005 | 0.98 | 164 |
| 2004 | 1.49 | 133 |
| 2003 | 1.17 | 137 |
| 2002 | 2.8 | 92 |
| 2001 | 0.62 | 155 |
| 2000 | 1.89 | 117 |
| 1999 | 0.68 | 130 |
| 1998 | 2.75 | 108 |
| 1997 | 1.04 | 152 |
| 1996 | 2.99 | 120 |
| 1995 | 6.12 | 104 |
| 1994 | 5.14 | 103 |
| 1993 | 5.18 | 89 |
| 1992 | 5.74 | 82 |
| 1991 | 7.99 | 79 |
| 1990 | 6.78 | 81 |
| 1989 | 3.26 | 106 |
| 1988 | 2.37 | 104 |
| 1987 | 2.7 | 95 |
| 1986 | 8.73 | 54 |