What is the number of annual ridership with a station that has more than 13 stations and larger than 4 lines?
CREATE TABLE "see_also" (
  "annual_ridership_2012" real,
  "rider_per_mile" real,
  "opened" real,
  "stations" real,
  "lines" real
);
SELECT SUM("annual_ridership_2012") FROM "see_also" WHERE "stations"=13 AND "lines">4;