What is the largest 1st LBSC number with a LBSC Name of northcote?
CREATE TABLE "references" (
  "1st_lbsc_no" real,
  "lbsc_name" text,
  "built" text,
  "2nd_lbsc_no" text,
  "1st_sr_no" text,
  "2ns_sr_no" text,
  "withdrawn" text
);
SELECT MAX("1st_lbsc_no") FROM "references" WHERE "lbsc_name"='northcote';