What is the 1979 number for Standing Rock Indian Reservation when the 1989 is less than 54.9?
CREATE TABLE "changes_in_poverty_rates_on_largest_rese" (
  "reservation" text,
  "location" text,
  "1969" real,
  "1979" real,
  "1989" real,
  "2000" real
);
SELECT SUM("1979") FROM "changes_in_poverty_rates_on_largest_rese" WHERE "reservation"='standing rock indian reservation' AND "1989"<54.9;