| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 3.87 | 26 |
| 2015 | 3.84 | 72 |
| 2014 | 2.18 | 114 |
| 2013 | 4.24 | 66 |
| 2012 | 3.29 | 90 |
| 2011 | 3.34 | 98 |
| 2010 | 2.36 | 118 |
| 2009 | 2.13 | 118 |
| 2008 | 5.02 | 88 |
| 2007 | 4.9 | 99 |
| 2006 | 9.9 | 37 |
| 2005 | 3.37 | 92 |
| 2004 | 2.18 | 110 |
| 2003 | 2.62 | 89 |
| 2002 | 1.31 | 121 |
| 2001 | 1.35 | 117 |
| 2000 | 6.08 | 39 |
| 1999 | 3.54 | 72 |
| 1998 | 1.5 | 118 |
| 1997 | 1.43 | 112 |
| 1996 | 1.27 | 93 |
| 1995 | 1.35 | 83 |
| 1994 | 0.59 | 109 |
| 1993 | 0.92 | 85 |
| 1992 | 0.89 | 68 |
| 1991 | 0.58 | 82 |
| 1990 | 0.29 | 104 |
| 1989 | 0.36 | 87 |
| 1988 | 0.61 | 64 |
| 1987 | 0.63 | 69 |
| 1986 | 0.48 | 68 |