CREATE TABLE "year_by_year" (
  "year" real,
  "record" text,
  "regular_season_finish" text,
  "playoffs" text,
  "avg_attend" real
);

Question: Name the year for american conference semifinals
SQL: SELECT "year" FROM "year_by_year" WHERE "playoffs"='american conference semifinals';

Question: Name the total number of years for quarterfinals
SQL: SELECT COUNT("year") FROM "year_by_year" WHERE "playoffs"='quarterfinals';