| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 4.39 | 22 |
| 2015 | 4.14 | 66 |
| 2014 | 3.95 | 68 |
| 2013 | 2.8 | 100 |
| 2012 | 3.51 | 82 |
| 2011 | 3.87 | 85 |
| 2010 | 4 | 72 |
| 2009 | 1.89 | 124 |
| 2008 | 2.99 | 121 |
| 2007 | 3.19 | 125 |
| 2006 | 1.75 | 147 |
| 2005 | 1.73 | 131 |
| 2004 | 2.72 | 95 |
| 2003 | 1.81 | 115 |
| 2002 | 3.27 | 75 |
| 2001 | 4.15 | 56 |
| 2000 | 5.03 | 52 |
| 1999 | 4.77 | 55 |
| 1998 | 3.69 | 58 |
| 1997 | 2.22 | 85 |
| 1996 | 1.32 | 91 |
| 1995 | 0.62 | 113 |
| 1994 | 0.55 | 112 |
| 1993 | 0.3 | 120 |
| 1992 | 0.51 | 87 |
| 1991 | 0.18 | 114 |
| 1990 | 0.21 | 107 |
| 1989 | 0.27 | 96 |
| 1988 | 0.85 | 54 |
| 1987 | 0.4 | 83 |
| 1986 | 0.13 | 92 |