CREATE TABLE table_203_717 (id DECIMAL, "number" DECIMAL, "year built" DECIMAL, "livery" TEXT, "current status" TEXT, "notes" TEXT)

how many of the tramways were built before the 1970s ?
SELECT COUNT(*) FROM table_203_717 WHERE "year built" < 1970
SELECT COUNT(*) FROM "table_203_717" WHERE "year built" < 1970