| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 5.32 | 61 |
| 2015 | 5.39 | 66 |
| 2014 | 5.8 | 69 |
| 2013 | 6.39 | 78 |
| 2012 | 6.31 | 74 |
| 2011 | 6.38 | 71 |
| 2010 | 6.85 | 77 |
| 2009 | 6.89 | 84 |
| 2008 | 5.98 | 80 |
| 2007 | 6.47 | 85 |
| 2006 | 6.8 | 83 |
| 2005 | 6.92 | 76 |
| 2004 | 7.32 | 83 |
| 2003 | 7.49 | 81 |
| 2002 | 6.9 | 79 |
| 2001 | 7.11 | 84 |
| 2000 | 6.32 | 68 |
| 1999 | 6.83 | 75 |
| 1998 | 6.36 | 67 |
| 1997 | 6.59 | 71 |
| 1996 | 6.83 | 75 |
| 1995 | 6.7 | 73 |
| 1994 | 6.58 | 71 |
| 1993 | 6.77 | 83 |
| 1992 | 6.83 | 83 |
| 1991 | 7.64 | 99 |