| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 9.867 | 51 |
| 2015 | 9.324 | 66 |
| 2014 | 8.699 | 81 |
| 2013 | 8.289 | 94 |
| 2012 | 8.652 | 95 |
| 2011 | 8.73 | 91 |
| 2010 | 9.72 | 82 |
| 2009 | 11.118 | 77 |
| 2008 | 13.737 | 55 |
| 2007 | 12.884 | 65 |
| 2006 | 11.181 | 76 |
| 2005 | 10.61 | 87 |
| 2004 | 11.389 | 78 |
| 2003 | 14.701 | 64 |
| 2002 | 13.838 | 71 |
| 2001 | 14.532 | 72 |
| 2000 | 15.278 | 71 |
| 1999 | 18.484 | 59 |
| 1998 | 20.719 | 54 |
| 1997 | 20.179 | 52 |
| 1996 | 19.16 | 62 |
| 1995 | 18.508 | 53 |
| 1994 | 17.053 | 53 |
| 1993 | 18.021 | 44 |
| 1992 | 20.213 | 35 |
| 1991 | 23.363 | 28 |