| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 7.45 | 8 |
| 2015 | 4.87 | 18 |
| 2014 | 4.95 | 15 |
| 2013 | 6 | 22 |
| 2012 | 4.15 | 46 |
| 2011 | 7.85 | 20 |
| 2010 | 7.24 | 23 |
| 2009 | 5.8 | 16 |
| 2008 | 5.61 | 41 |
| 2007 | 7.72 | 33 |
| 2006 | 6.86 | 35 |
| 2005 | 6.94 | 36 |
| 2004 | 3.49 | 74 |
| 2003 | 4.22 | 50 |
| 2002 | 1.17 | 86 |
| 2001 | 4.17 | 32 |
| 2000 | 1.65 | 80 |
| 1999 | 0.34 | 90 |
| 1998 | 4.55 | 39 |
| 1997 | 1.08 | 90 |
| 1996 | 5.75 | 34 |
| 1995 | 4.07 | 39 |
| 1994 | 2.84 | 40 |
| 1993 | 2.31 | 41 |
| 1992 | 0.54 | 61 |
| 1991 | 0.1 | 66 |
| 1990 | 2.32 | 35 |
| 1989 | 2.77 | 38 |
| 1988 | 3.99 | 33 |
| 1987 | 1.2 | 52 |
| 1986 | 0.89 | 55 |