| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 3.1 | 59 |
| 2015 | 3.07 | 74 |
| 2014 | 3.01 | 83 |
| 2013 | 3 | 88 |
| 2012 | 2.92 | 78 |
| 2011 | 2.72 | 107 |
| 2010 | 3.47 | 65 |
| 2009 | 3.17 | 77 |
| 2008 | 3.35 | 90 |
| 2007 | 3.68 | 73 |
| 2006 | 3.25 | 84 |
| 2005 | 3.26 | 65 |
| 2004 | 2.76 | 98 |
| 2003 | 3.48 | 67 |
| 2002 | 3.6 | 63 |
| 2001 | 3.71 | 66 |
| 2000 | 3.4 | 69 |
| 1999 | 3.5 | 75 |
| 1998 | 3.61 | 62 |
| 1997 | 3.43 | 60 |
| 1996 | 3.07 | 80 |
| 1995 | 2.9 | 74 |
| 1994 | 3.83 | 44 |
| 1993 | 2.49 | 57 |
| 1992 | 1.96 | 68 |
| 1991 | 2.45 | 56 |
| 1990 | 2.77 | 59 |
| 1989 | 2.92 | 61 |
| 1988 | 3.62 | 50 |
| 1987 | 2.09 | 57 |
| 1986 | 2.11 | 59 |