Year Total 1960 150.9 1961 157.9 1962 170 1963 184.4 1964 198.9 1965 201.4 1966 222.4 1967 241.2 1968 272.7 1969 310.4 1970 395 1971 422.9 1972 458.9 1973 541.3 1974 530.8 1975 578.6 1976 614.9 1977 676.6 1978 709.2 1979 844.9 1980 904.1 1981 1096 1982 1162 1983 1230 1984 1251 1985 1252 1986 1276 1987 1316 1988 1372 1989 1410 1990 1400 1991 1437 1992 1390 1993 1491 1994 1481 1995 1565 1996 1616 1997 1682 1998 1814 1999 2191 2000 2306 2001 2451 2002 2462 2003 2457 2004 2519 2005 2636 2006 3259 2007 3952 2008 4355 2009 4402 2010 4568