12.  Section 80C on earlier occasions was amended by the Finance Act, 1968, w.e.f. 1-4-1969, Finance Act, 1969, w.e.f. 1-4-1970, Finance Act, 1970, w.e.f. 1-4-1971, Finance (No. 2) Act, 1971, w.e.f. 1-4-1972, Finance Act, 1972, w.e.f. 1-4-1973, Finance Act, 1973, w.e.f. 1-4-1974, Finance Act, 1975, w.e.f. 1-4-1976, Finance Act, 1976, w.e.f. 1-4-1977, Finance Act, 1978, w.e.f. 1-4-1979, Finance Act, 1979, w.e.f. 1-4-1980, Finance (No. 2) Act, 1980, w.e.f. 1-4-1981, Finance Act, 1982, w.e.f. 1-4-1983, Finance Act, 1983, w.e.f. 1-4-1984, Taxation Laws (Amendment) Act, 1984, w.r.e.f. 1-4-1971, Taxation Laws (Amendment) Act, 1984, w.r.e.f. 1-4-1983, Finance Act, 1987, w.e.f. 1-4-1988, Direct Tax Laws (Amendment) Act, 1989, w.e.f. 1-4-1989, Direct Tax Laws (Second Amdt.) Act, 1989, w.r.e.f. 1-4-1984, Direct Tax Laws (Second Amdt.) Act, 1989, w.e.f. 1-4-1990 and Finance Act, 1989, w.e.f. 1-4-1990.