CREATE TABLE table_name_74 (year_s__of_manufacture VARCHAR2, quantity VARCHAR2, axle_arrangement___uic__ VARCHAR2)

What year was the b n2t axle arrangement, which has a quantity of 31, manufactured?
SELECT year_s__of_manufacture FROM table_name_74 WHERE quantity = 31 AND axle_arrangement___uic__ = "b n2t"
SELECT "year_s__of_manufacture" FROM "table_name_74" WHERE "axle_arrangement___uic__" = "b n2t" AND "quantity" = 31