What is the Total with the Event 2004 Athens and Gold less than 20?
CREATE TABLE "summer_paralympics" (
  "event" text,
  "gold" real,
  "silver" real,
  "bronze" real,
  "total" real,
  "ranking" text
);
SELECT SUM("total") FROM "summer_paralympics" WHERE "event"='2004 athens' AND "gold"<20;