How many times was the candidates paul tsongas (d) 60.6% paul w. cronin (r) 39.4%?
CREATE TABLE "united_states_house_of_representatives_e" (
  "district" text,
  "incumbent" text,
  "party" text,
  "first_elected" real,
  "result" text,
  "candidates" text
);
SELECT COUNT("incumbent") FROM "united_states_house_of_representatives_e" WHERE "candidates"='Paul Tsongas (D) 60.6% Paul W. Cronin (R) 39.4%';