What was the highest number of WJC Jews that had a WJC rank of 6 and a ARDA rank of more than 8?
CREATE TABLE "metropolitan_areas_with_largest_jewish_p" (
  "rank_wjc" real,
  "rank_arda" real,
  "metro_area" text,
  "number_of_jews_wjc" real,
  "number_of_jews_asarb" real
);
SELECT MAX("number_of_jews_wjc") FROM "metropolitan_areas_with_largest_jewish_p" WHERE "rank_wjc"=6 AND "rank_arda">8;