Table:
text: Northwestern Conference (IHSAA)
Former members
Former members
School City Mascot County Year_joined Previous_Conference Year_Left Conference_Joined
East Chicago Roosevelt East Chicago Roughriders 45 Lake 1963 Northern Indiana 1968 Indiana Lake Shore
East Chicago Washington East Chicago Senators 45 Lake 1963 Northern Indiana 1968 Indiana Lake Shore
Gary Emerson Gary Tornado 45 Lake 1963 Northern Indiana 1981 none (school closed, reopened as Emerson VPA)
Gary Froebel Gary Blue Devils 45 Lake 1963 Northern Indiana 1969 none (school became MS, closed 1977)
Gary Mann Gary Horsemen 45 Lake 1963 Northern Indiana 2004 none (school closed)
Gary Tolleston Gary Blue Raiders 45 Lake 1963 Northern Indiana 1969 none (school became MS, closed 2007)

Question: In what year did Roughriders of the Northwestern Conference (IHSAA) leave the conference?