user: Question: What district is St Martin's Without parish in with a population less than 75?
Columns: ['Name', 'Status', 'Population', 'District', 'Former local authority']
Types: ['text', 'text', 'real', 'text', 'text']
Sample row: ['Cambridge', 'Unparished area', 108863.0, 'Cambridge', 'Cambridge Municipal Borough']
SQL:

assistant: SELECT "District" FROM "Table" WHERE "Population" < 75.0 AND "Name" = 'St Martin''s Without';