How many elapsed times were recorded for the game that had a prize pool of $1,678,200?
CREATE TABLE "2011_events" (
  "date" text,
  "event_num" text,
  "event" text,
  "winner" text,
  "prize" text,
  "entries" text,
  "prize_pool" text,
  "elapsed_time" text
);
SELECT COUNT("elapsed_time") FROM "2011_events" WHERE "prize_pool"='$1,678,200';