| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 45.2 | 15 |
| 2015 | 49.5 | 16 |
| 2014 | 46.6 | 23 |
| 2013 | 36.4 | 22 |
| 2012 | 49.3 | 17 |
| 2011 | 83.6 | 14 |
| 2010 | 71.8 | 14 |
| 2009 | 91.4 | 10 |
| 2008 | 186.2 | 9 |
| 2007 | 114.9 | 10 |
| 2006 | 100.7 | 11 |
| 2005 | 74.2 | 15 |
| 2004 | 64.7 | 18 |
| 2003 | 51 | 22 |
| 2002 | 56.9 | 17 |
| 2001 | 76.1 | 17 |
| 2000 | 91.8 | 10 |
| 1999 | 78.3 | 6 |
| 1998 | 85.8 | 11 |
| 1997 | 68.9 | 13 |
| 1996 | 62.2 | 10 |
| 1995 | 54.9 | 9 |
| 1994 | 49.9 | 13 |
| 1993 | 60.8 | 8 |
| 1992 | 51.1 | 6 |
| 1991 | 57.3 | 4 |
| 1990 | 56.8 | 9 |
| 1989 | 51.5 | 8 |
| 1988 | 30.6 | 11 |
| 1987 | 81.1 | 6 |
| 1986 | 16.8 | 17 |