How many lanes had a rank smaller than 4 and a time of 2:01.51?
CREATE TABLE "semifinal_2" (
  "rank" real,
  "lane" real,
  "name" text,
  "nationality" text,
  "time" text
);
SELECT COUNT("lane") FROM "semifinal_2" WHERE "time"='2:01.51' AND "rank"<4;