Year Number 1961 235.37735849056602 1962 275.24271844660194 1963 290.625 1964 316.45962732919253 1965 335.5769230769231 1966 354.9689440993789 1967 383.74613003095976 1968 427.48447204968943 1969 483.0218068535825 1970 503.3846153846154 1971 490.9509202453988 1972 512.4615384615385 1973 533.8323353293413 1974 576.2536873156341 1975 572.9166666666667 1976 649.2307692307693 1977 703.0769230769231 1978 747.6923076923077 1979 787.6923076923077 1980 824.6153846153845 1981 815.3846153846154 1982 824.6153846153845 1983 872.2222222222222 1984 819.2073170731707 1985 802.874617737003 1986 835.7396449704142 1987 845.4867256637168 1988 839.0560471976402 1989 840.2366863905324 1990 798.8338192419825 1991 746.9740634005764 1992 743.2276657060519 1993 734.8703170028818 1994 724.9283667621777 1995 721.7391304347826 1996 732.7380952380953 1997 724.5535714285714 1998 718.3582089552239 1999 714.2642642642643 2000 695.2662721893491 2001 679.2397660818714 2002 657.5931232091691 2003 678.7425149700598 2004 720.096463022508 2005 711.0932475884244 2006 721.1221122112211 2007 705.0359712230215 2008 710.0433767100434