| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2015 | 2.57 | 96 |
| 2014 | 4.17 | 67 |
| 2013 | 5.28 | 49 |
| 2012 | 5.01 | 62 |
| 2011 | 5.61 | 58 |
| 2010 | 5.44 | 57 |
| 2009 | 5.06 | 63 |
| 2008 | 7.05 | 65 |
| 2007 | 5.8 | 89 |
| 2006 | 7.7 | 53 |
| 2005 | 4.76 | 71 |
| 2004 | 2.58 | 100 |
| 2003 | 3.34 | 70 |
| 2002 | 1.32 | 120 |
| 2001 | 1.49 | 114 |
| 2000 | 1.15 | 127 |
| 1999 | 0.98 | 121 |
| 1998 | 0.65 | 139 |
| 1997 | 0.53 | 141 |
| 1996 | 0.67 | 121 |
| 1995 | 0.81 | 101 |
| 1994 | 0.88 | 95 |
| 1993 | 0.68 | 98 |
| 1992 | 0.09 | 122 |
| 1991 | 0.29 | 101 |
| 1990 | 0.45 | 97 |
| 1989 | 0.45 | 81 |
| 1988 | 0.57 | 67 |
| 1987 | 0.68 | 65 |
| 1986 | 0.63 | 55 |