CREATE TABLE table_204_514 (id DECIMAL, "date" TEXT, "sub" DECIMAL, "flight" TEXT, "dead" DECIMAL, "hurt" DECIMAL, "pax." DECIMAL, "type" TEXT, "perpetrator" TEXT, "description" TEXT)

how many people were killed in total in the attacks in 1973 and 1974 ?
SELECT SUM("dead") FROM table_204_514 WHERE "date" IN (1973, 1974)
SELECT SUM("dead") FROM "table_204_514" WHERE "date" IN (1973, 1974)