CREATE TABLE table_18594 ("District" CLOB, "Incumbent" CLOB, "Party" CLOB, "First elected" FLOAT, "Result" CLOB, "Candidates" CLOB)

What is the first electedfor district ohio 18
SELECT "First elected" FROM table_18594 WHERE "District" = 'Ohio 18'
SELECT "First elected" FROM "table_18594" WHERE "District" = 'Ohio 18'