| | 1980 | | | 1981 | | 1982 | | 1983 | | 1984 | | 1985 | | | 1986 | | 1987 | | 1988 | | 1989 | | 1990 | | | 1991 | | 1992 | | 1993 | | 1994 | | 1995 | | | 1996 | | 1997 | | 1998 | | 1999 | | 2000 | | | 2001 | | 2002 | | 2003 | | 2004 | | 2005 | | | 2006 | | 2007 | | 2008 | | |
|
| | | | | | 1907.7 | 65.3 | 33.5 | | 1.2 | | | | | | | 1902.6 | 64.9 | 34.5 | | 0.6 | | 1920.4 | 65.9 | 33.6 | | 0.5 | | 1984.7 | 67.6 | 31.8 | | 0.6 | | 2144.1 | 68.0 | 31.6 | | 0.4 | | 2211.4 | 68.7 | 31.0 | | 0.3 | | | | | | | 2400.0 | 68.2 | 31.4 | 0.1 | 0.3 | | 2475.8 | 69.3 | 30.3 | 0.1 | 0.3 | | 2612.6 | 69.9 | 29.8 | 0.1 | 0.2 | | 2653.2 | 69.5 | 29.8 | 0.4 | 0.3 | | 2709.7 | 70.7 | 28.7 | 0.4 | 0.2 | | | | | | | 2872.0 | 71.1 | 28.2 | 0.4 | 0.3 | | 2987.5 | 70.9 | 28.4 | 0.4 | 0.3 | | 3264.6 | 72.4 | 27.0 | 0.4 | 0.2 | | 3385.9 | 75.6 | 23.8 | 0.4 | 0.2 | | 3533.3 | 74.2 | 25.1 | 0.4 | 0.3 | | | | | | | 3734.5 | 72.0 | 26.9 | 0.5 | 0.6 | | 3719.2 | 72.8 | 25.8 | 0.6 | 0.8 | | 3808.1 | 73.5 | 24.4 | 1.3 | 0.8 | | 3906.6 | 71.6 | 25.2 | 2.5 | 0.7 | | 4144.0 | 72.1 | 24.1 | 3.1 | 0.7 | | | | | | | 4229.2 | 71.3 | 23.9 | 4.7 | 0.1 | | 4436.1 | 67.1 | 27.2 | 5.6 | 0.1 | | 4648.2 | 69.0 | 25.4 | 5.5 | 0.1 | | 5139.6 | 65.8 | 27.8 | 6.4 | 0.0 | | 5521.9 | 64.0 | 28.9 | 7.0 | 0.1 | | | | | | | 5904.1 | 61.6 | 30.0 | 8.4 | … | | 6285.0 | 60.2 | 30.8 | 9.0 | … | | 6343.7 | | | | | | | | | | | | | | | |