| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 2.52 | 40 |
| 2015 | 2.12 | 108 |
| 2014 | 2.6 | 107 |
| 2013 | 3.84 | 74 |
| 2012 | 1.86 | 128 |
| 2011 | 2.14 | 123 |
| 2010 | 2.87 | 103 |
| 2009 | 0.9 | 150 |
| 2008 | 4.87 | 90 |
| 2007 | 4.99 | 98 |
| 2006 | 2.61 | 128 |
| 2005 | 2.31 | 113 |
| 2004 | 2.35 | 105 |
| 2003 | 3.39 | 69 |
| 2002 | 5.59 | 36 |
| 2001 | 4.62 | 48 |
| 2000 | 6.8 | 33 |
| 1999 | 2.93 | 84 |
| 1998 | 2.31 | 94 |
| 1997 | 1.52 | 109 |
| 1996 | 1.5 | 84 |
| 1995 | 1.32 | 84 |
| 1994 | 1.74 | 59 |
| 1993 | 1.85 | 47 |
| 1992 | 2.11 | 38 |
| 1991 | 2.17 | 40 |
| 1990 | 2.61 | 31 |
| 1989 | 2.04 | 34 |
| 1988 | 1.87 | 31 |
| 1987 | 1.44 | 35 |
| 1986 | 1.38 | 34 |