table: [['district', 'incumbent', 'party', 'first elected', 'results'], ['massachusetts 1', 'john olver', 'democratic', '1991', 're - elected'], ['massachusetts 2', 'richard neal', 'democratic', '1988', 're - elected'], ['massachusetts 3', 'jim mcgovern', 'democratic', '1996', 're - elected'], ['massachusetts 4', 'barney frank', 'democratic', '1980', 're - elected'], ['massachusetts 5', 'marty meehan', 'democratic', '1992', 're - elected'], ['massachusetts 6', 'john tierney', 'democratic', '1996', 're - elected'], ['massachusetts 7', 'ed markey', 'democratic', '1976', 're - elected'], ['massachusetts 8', 'mike capuano', 'democratic', '1998', 're - elected'], ['massachusetts 9', 'stephen lynch', 'democratic', '2001', 're - elected'], ['massachusetts 10', 'bill delahunt', 'democratic', '1996', 're - elected']]
ref: John Olver is the only Incumbent Re - Elected in 1991
template: [ENT] is the only [ENT] [ENT] in [ENT]