| 时间 | 值 | 世界排名 |
|---|---|---|
| 2016 | 13.2 | 6 |
| 2015 | 12.4 | 12 |
| 2014 | 8.5 | 18 |
| 2013 | 10.3 | 14 |
| 2012 | 11.5 | 12 |
| 2011 | 11.6 | 11 |
| 2010 | 14.2 | 9 |
| 2009 | 16.5 | 9 |
| 2008 | 10.8 | 12 |
| 2007 | 16 | 6 |
| 2006 | 13.6 | 8 |
| 2005 | 10.9 | 8 |
| 2004 | 9.9 | 10 |
| 2003 | 7.5 | 19 |
| 2002 | 6.1 | 29 |
| 2001 | 5.2 | 30 |
| 2000 | 4.7 | 33 |
| 1999 | 2.4 | 95 |
| 1998 | 1.6 | 112 |
| 1997 | 2 | 97 |
| 1996 | 2 | 93 |
| 1995 | 2.4 | 76 |
| 1994 | 1.2 | 114 |