| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 9.75 | 63 |
| 2015 | 9.39 | 70 |
| 2014 | 8.33 | 88 |
| 2013 | 8.81 | 87 |
| 2012 | 2.84 | 135 |
| 2011 | 6.47 | 113 |
| 2010 | 6.82 | 119 |
| 2009 | 9.03 | 88 |
| 2008 | 17.49 | 64 |
| 2007 | 33.83 | 36 |
| 2006 | 14.13 | 108 |
| 2005 | 20.04 | 52 |
| 2004 | 48.42 | 7 |
| 2003 | 21.07 | 42 |
| 2002 | 46.6 | 7 |
| 2001 | 18.02 | 69 |
| 2000 | 40.81 | 22 |
| 1999 | 50.4 | 9 |
| 1998 | 53.75 | 8 |
| 1997 | 113.43 | 4 |
| 1996 | 69.55 | 6 |
| 1995 | 69.62 | 9 |
| 1994 | 125.45 | 11 |
| 1993 | 172.17 | 8 |
| 1992 | 94.7 | 7 |
| 1991 | 104.02 | 6 |
| 1990 | 30.09 | 29 |
| 1989 | 5.31 | 109 |
| 1988 | 10.26 | 83 |
| 1987 | 3.94 | 102 |
| 1986 | 8.43 | 92 |