CREATE TABLE table_23181 ("Institution" TEXT, "Location" TEXT, "Nickname" TEXT, "Founded" FLOAT, "Type" TEXT, "Enrollment" FLOAT, "Joined" FLOAT)

When was the private/non-sectarian school founded?
SELECT "Founded" FROM table_23181 WHERE "Type" = 'Private/Non-sectarian'
SELECT "Founded" FROM "table_23181" WHERE "Type" = 'Private/Non-sectarian'