| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 2.43 | 42 |
| 2015 | 5.53 | 55 |
| 2014 | 3.64 | 75 |
| 2013 | 3.57 | 84 |
| 2012 | 3.32 | 89 |
| 2011 | 3.66 | 91 |
| 2010 | 3.64 | 81 |
| 2009 | 7.52 | 43 |
| 2008 | 18.84 | 13 |
| 2007 | 31 | 5 |
| 2006 | 22.95 | 11 |
| 2005 | 13.74 | 17 |
| 2004 | 11.77 | 14 |
| 2003 | 9.95 | 20 |
| 2002 | 5.53 | 38 |
| 2001 | 5.75 | 35 |
| 2000 | 7.62 | 26 |
| 1999 | 6.07 | 44 |
| 1998 | 3.67 | 59 |
| 1997 | 4.51 | 42 |
| 1996 | 1.08 | 105 |
| 1995 | 0.69 | 108 |
| 1994 | 1.09 | 85 |
| 1993 | 0.37 | 111 |
| 1992 | 0.4 | 95 |
| 1991 | 0.51 | 88 |
| 1990 | 0.02 | 124 |