CREATE TABLE table_2020 ("Fiscal year" FLOAT, "2-car sets" FLOAT, "4-car sets" FLOAT, "6-car sets" FLOAT, "8-car sets" FLOAT, "Total vehicles" FLOAT)

What is the largest 6-car-sets for fiscal year 1968?
SELECT MAX("6-car sets") FROM table_2020 WHERE "Fiscal year" = '1968'
SELECT MAX("6-car sets") FROM "table_2020" WHERE "Fiscal year" = '1968'