Who was the lap-by-lap broadcaster before 1994 who garnered ratings of 8.0/21?
CREATE TABLE "cbs_era_1979_2000" (
  "year" real,
  "network" text,
  "lap_by_lap" text,
  "color_commentator_s" text,
  "pit_reporters" text,
  "host" text,
  "ratings" text,
  "viewers" text
);
SELECT "lap_by_lap" FROM "cbs_era_1979_2000" WHERE "year"<1994 AND "ratings"='8.0/21';