| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 5.87 | 74 |
| 2015 | 5.9 | 73 |
| 2014 | 5.6 | 65 |
| 2013 | 6.24 | 77 |
| 2012 | 5.99 | 68 |
| 2011 | 5.95 | 67 |
| 2010 | 5.55 | 55 |
| 2009 | 5.46 | 55 |
| 2008 | 4.98 | 56 |
| 2007 | 5.1 | 59 |
| 2006 | 6.09 | 68 |
| 2005 | 7.7 | 93 |
| 2004 | 7.4 | 85 |
| 2003 | 8.3 | 96 |
| 2002 | 7.83 | 92 |
| 2001 | 7.8 | 95 |
| 2000 | 7.16 | 86 |
| 1999 | 5.9 | 58 |
| 1998 | 5.7 | 59 |
| 1997 | 5.81 | 62 |
| 1996 | 5.4 | 53 |
| 1995 | 5.03 | 49 |
| 1994 | 4.26 | 43 |
| 1993 | 4.28 | 46 |
| 1992 | 5.18 | 57 |
| 1991 | 5.85 | 70 |