What year did the team make conference semifinals?
CREATE TABLE "year_by_year" (
  "year" real,
  "division" text,
  "league" text,
  "regular_season" text,
  "playoffs" text,
  "u_s_open_cup" text,
  "avg_attendance" text
);
SELECT COUNT("year") FROM "year_by_year" WHERE "playoffs"='conference semifinals';