| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 5.647 | 36 |
| 2015 | 4.713 | 50 |
| 2014 | 4.248 | 57 |
| 2013 | 3.978 | 65 |
| 2012 | 4.209 | 70 |
| 2011 | 4.283 | 66 |
| 2010 | 4.997 | 62 |
| 2009 | 6.242 | 63 |
| 2008 | 8.384 | 44 |
| 2007 | 7.547 | 48 |
| 2006 | 6.298 | 58 |
| 2005 | 6.24 | 55 |
| 2004 | 6.352 | 50 |
| 2003 | 8.755 | 39 |
| 2002 | 7.809 | 50 |
| 2001 | 6.794 | 62 |
| 2000 | 7.39 | 73 |
| 1999 | 10.816 | 48 |
| 1998 | 12.94 | 41 |
| 1997 | 12.701 | 44 |
| 1996 | 12.56 | 53 |
| 1995 | 10.843 | 60 |
| 1994 | 9.181 | 56 |
| 1993 | 9.612 | 52 |
| 1992 | 11.362 | 46 |
| 1991 | 12.774 | 39 |