CREATE TABLE table_54086 ("House Name" CLOB, "Composition" CLOB, "Named after" CLOB, "Founded" FLOAT, "Colours" CLOB)

When is the earliest year founded for houses named after the river benue?
SELECT MIN("Founded") FROM table_54086 WHERE "Named after" = 'river benue'
SELECT MIN("Founded") FROM "table_54086" WHERE "Named after" = 'river benue'