user: Question: Which class has less in quantity than 174 between the years 1921–23?
Columns: ['Class', 'Type', 'Quantity', 'Date', 'LNER Class', '1946 LNER nos.']
Types: ['text', 'text', 'real', 'text', 'text', 'text']
Sample row: ['8C', '4-6-0', 2.0, '1903–04', 'B1', '1479–80']
SQL:

assistant: SELECT "Class" FROM "Table" WHERE "Quantity" < 174.0 AND "Date" = '1921–23';