| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 4.79 | 18 |
| 2015 | 5.01 | 17 |
| 2014 | 4.18 | 34 |
| 2013 | 0.54 | 135 |
| 2012 | 3.33 | 58 |
| 2011 | 6.02 | 27 |
| 2010 | 9.71 | 7 |
| 2009 | 4.64 | 15 |
| 2008 | 2.68 | 90 |
| 2007 | 15.4 | 3 |
| 2006 | 4.37 | 87 |
| 2005 | 4.45 | 71 |
| 2004 | 3.11 | 113 |
| 2003 | 4.72 | 55 |
| 2002 | 7.66 | 13 |
| 2001 | 5.23 | 30 |
| 2000 | 3.97 | 69 |
| 1999 | 5 | 33 |
| 1998 | 3.3 | 75 |
| 1997 | 3.49 | 74 |
| 1996 | 4.67 | 50 |
| 1995 | 7.41 | 16 |
| 1994 | 6.3 | 20 |
| 1993 | 3.63 | 41 |
| 1992 | 5.73 | 28 |
| 1991 | -.41 | 101 |
| 1990 | 9.43 | 10 |
| 1989 | 4.8 | 37 |
| 1988 | 1.57 | 101 |
| 1987 | 24.2 | 1 |
| 1986 | 8.08 | 12 |