| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 3.07 | 79 |
| 2015 | 4.14 | 54 |
| 2014 | 4.17 | 73 |
| 2013 | 3.7 | 85 |
| 2012 | 2.97 | 107 |
| 2011 | 4.16 | 92 |
| 2010 | 2.87 | 128 |
| 2009 | 0.53 | 96 |
| 2008 | 3.28 | 113 |
| 2007 | 6.3 | 89 |
| 2006 | 5.38 | 102 |
| 2005 | 3.26 | 141 |
| 2004 | 3.15 | 151 |
| 2003 | 2.53 | 136 |
| 2002 | 3.87 | 81 |
| 2001 | 2.33 | 117 |
| 2000 | 3.61 | 128 |
| 1999 | 3.85 | 80 |
| 1998 | 4.99 | 57 |
| 1997 | 4.36 | 96 |
| 1996 | 2.96 | 121 |
| 1995 | 4.95 | 72 |
| 1994 | 4.03 | 79 |
| 1993 | 3.93 | 73 |
| 1992 | 4.84 | 54 |
| 1991 | 3.66 | 62 |
| 1990 | 3.1 | 89 |
| 1989 | 3.94 | 80 |
| 1988 | 3.89 | 96 |
| 1987 | 3.54 | 79 |
| 1986 | 0.14 | 129 |