What is the number of silver when the total is more than 2, and bronze is less than 3, with  a rank of 7?
CREATE TABLE "world_championships_total_medals" (
  "rank" text,
  "nation" text,
  "gold" real,
  "silver" real,
  "bronze" real,
  "total" real
);
SELECT COUNT("silver") FROM "world_championships_total_medals" WHERE "total">2 AND "bronze"<3 AND "rank"='7';