What was the highest number of 2009 electorates for Raisen when the consituency number was 142?
CREATE TABLE "assembly_segments" (
  "constituency_number" text,
  "name" text,
  "reserved_for_sc_st_none" text,
  "district" text,
  "number_of_electorates_2009" real
);
SELECT MAX("number_of_electorates_2009") FROM "assembly_segments" WHERE "district"='raisen' AND "constituency_number"='142';