| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 3.63 | 38 |
| 2015 | 4.06 | 53 |
| 2014 | 5.78 | 42 |
| 2013 | 5.72 | 49 |
| 2012 | 4.59 | 74 |
| 2011 | 9.81 | 30 |
| 2010 | 2.5 | 113 |
| 2009 | 3.35 | 84 |
| 2008 | 14 | 39 |
| 2007 | 8.71 | 39 |
| 2006 | 4.29 | 93 |
| 2005 | 5.39 | 73 |
| 2004 | 4.44 | 72 |
| 2003 | 3.34 | 85 |
| 2002 | 0.93 | 141 |
| 2001 | 1.59 | 140 |
| 2000 | 4.61 | 64 |
| 1999 | 2.16 | 104 |
| 1998 | 7.67 | 61 |
| 1997 | 4.71 | 88 |
| 1996 | 12.43 | 51 |
| 1995 | 10.19 | 71 |
| 1994 | 7.87 | 91 |
| 1993 | 8.53 | 76 |
| 1992 | 12.06 | 50 |
| 1991 | 21.45 | 38 |
| 1990 | 17.12 | 41 |
| 1989 | 15.17 | 36 |
| 1988 | 16 | 37 |
| 1987 | 14.58 | 37 |
| 1986 | 276.34 | 2 |