| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 10.91 | 51 |
| 2015 | 2.34 | 126 |
| 2014 | 5.01 | 123 |
| 2013 | 12.44 | 65 |
| 2012 | 16.8 | 38 |
| 2011 | 12.99 | 65 |
| 2010 | 6.79 | 120 |
| 2009 | 17.21 | 49 |
| 2008 | 58.53 | 3 |
| 2007 | 64.92 | 4 |
| 2006 | 36.35 | 24 |
| 2005 | 22.6 | 43 |
| 2004 | 20.68 | 46 |
| 2003 | 13.51 | 78 |
| 2002 | 18.82 | 50 |
| 2001 | 26.38 | 45 |
| 2000 | 48.07 | 12 |
| 1999 | 33.12 | 18 |
| 1998 | 22.32 | 26 |
| 1997 | 16.04 | 83 |
| 1996 | 16.18 | 73 |
| 1995 | 19.41 | 63 |
| 1994 | 34.5 | 43 |
| 1993 | 53.76 | 19 |
| 1992 | 63.26 | 13 |
| 1991 | 37.38 | 25 |
| 1990 | 32.7 | 28 |
| 1989 | 12.93 | 79 |
| 1988 | 32.91 | 23 |
| 1987 | 22.41 | 42 |
| 1986 | 1.95 | 108 |