| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 136.5 | 4 |
| 2015 | 73.7 | 8 |
| 2014 | 70 | 13 |
| 2013 | 63.3 | 11 |
| 2012 | 57.2 | 13 |
| 2011 | 54.2 | 14 |
| 2010 | 73.9 | 12 |
| 2009 | 73.5 | 14 |
| 2008 | 70.7 | 18 |
| 2007 | 86.1 | 21 |
| 2006 | 64 | 18 |
| 2005 | 43.2 | 21 |
| 2004 | 36.6 | 24 |
| 2003 | 28 | 23 |
| 2002 | 41.3 | 18 |
| 2001 | 29.1 | 22 |
| 2000 | 51.7 | 21 |
| 1999 | 53.3 | 15 |
| 1998 | 39.4 | 16 |
| 1997 | 27.6 | 17 |
| 1996 | 18.1 | 19 |
| 1995 | 10.3 | 28 |
| 1994 | 9.6 | 30 |
| 1993 | 5.9 | 32 |
| 1992 | 5.4 | 25 |
| 1991 | 6.5 | 22 |
| 1990 | 7.1 | 21 |
| 1989 | 5.7 | 25 |
| 1988 | 3.7 | 25 |
| 1987 | 9.2 | 20 |
| 1986 | 6.3 | 17 |