user: Question: Which chapter was active from 1906-1991?
Columns: ['Chapter', 'Chartered', 'School', 'State', 'Status', 'Charter Range']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Alpha', '1873', 'University of Massachusetts Amherst', 'Massachusetts', 'Active', '1873-Present']
SQL:

assistant: SELECT "Chapter" FROM "Table" WHERE "Charter Range" = '1906-1991';