| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 3.21 | 27 |
| 2015 | 3.03 | 25 |
| 2014 | 3 | 24 |
| 2013 | 3.3 | 29 |
| 2012 | 2.45 | 18 |
| 2011 | 3.22 | 24 |
| 2010 | 2.53 | 15 |
| 2009 | 1.92 | 13 |
| 2008 | 2.1 | 16 |
| 2007 | 3.17 | 27 |
| 2006 | 3.17 | 25 |
| 2005 | 3.18 | 24 |
| 2004 | 2.2 | 13 |
| 2003 | 3.27 | 22 |
| 2002 | 2.9 | 20 |
| 2001 | 3.81 | 35 |
| 2000 | 2.04 | 15 |
| 1999 | 1.85 | 12 |
| 1998 | 3.08 | 23 |
| 1997 | 3.79 | 37 |
| 1996 | 4.5 | 41 |
| 1995 | 3.17 | 26 |
| 1994 | 3.19 | 31 |
| 1993 | 3.21 | 32 |
| 1992 | 3.22 | 31 |
| 1991 | 2.54 | 23 |