Year Total 1970 161220000 1971 173000000 1972 180330000 1973 192460000 1974 212250000 1975 235600000 1976 261410000 1977 281810000 1978 303140000 1979 331160000 1980 354460000 1981 378980000 1982 407810000 1983 436320000 1984 478430000