| 时间 | 值 | 世界排名 |
|---|---|---|
| 2016 | 17.1 | 2 |
| 2015 | 16.8 | 5 |
| 2014 | 14.2 | 5 |
| 2013 | 15 | 6 |
| 2012 | 14.2 | 7 |
| 2011 | 15.2 | 7 |
| 2010 | 15.7 | 8 |
| 2009 | 18.3 | 6 |
| 2008 | 13.3 | 9 |
| 2007 | 15 | 7 |
| 2006 | 15 | 7 |
| 2005 | 15.8 | 6 |
| 2004 | 18 | 2 |
| 2003 | 17.1 | 2 |
| 2002 | 13.1 | 4 |
| 2001 | 10.7 | 4 |
| 2000 | 8.8 | 5 |
| 1999 | 8.2 | 5 |
| 1998 | 6.6 | 10 |
| 1997 | 5.7 | 15 |
| 1996 | 5.4 | 20 |