Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_74 ( year_s__of_manufacture VARCHAR, quantity VARCHAR, axle_arrangement___uic__ VARCHAR )

### Question ###
What year was the b n2t axle arrangement, which has a quantity of 31, manufactured?

### Accurate SQL ###

SELECT year_s__of_manufacture FROM table_name_74 WHERE quantity = 31 AND axle_arrangement___uic__ = "b n2t"