| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 4.83 | 94 |
| 2015 | 13.2 | 47 |
| 2014 | 15 | 34 |
| 2013 | 20.94 | 18 |
| 2012 | 11.76 | 67 |
| 2011 | 16.09 | 51 |
| 2010 | 19.02 | 46 |
| 2009 | 20.99 | 34 |
| 2008 | 34.58 | 14 |
| 2007 | 29.93 | 42 |
| 2006 | 10.71 | 132 |
| 2005 | 11.07 | 106 |
| 2004 | 15.1 | 72 |
| 2003 | 10.92 | 92 |
| 2002 | 1.46 | 141 |
| 2001 | 39.57 | 26 |
| 2000 | 2.84 | 135 |
| 1999 | 12.85 | 89 |
| 1998 | 7.62 | 102 |
| 1997 | 5.21 | 131 |
| 1996 | 9.81 | 102 |
| 1995 | 0.53 | 142 |
| 1994 | 24.23 | 63 |
| 1993 | 27.93 | 43 |
| 1992 | 37.13 | 28 |
| 1991 | 49.75 | 15 |
| 1990 | 53.91 | 14 |
| 1989 | 58.86 | 13 |
| 1988 | 27.11 | 33 |
| 1987 | 35 | 25 |
| 1986 | 27.37 | 25 |