CREATE TABLE table_18166 ("District" TEXT, "Incumbent" TEXT, "Party" TEXT, "First elected" FLOAT, "Results" TEXT, "Candidates" TEXT)

What year was Bob Clement first elected?
SELECT MIN("First elected") FROM table_18166 WHERE "Incumbent" = 'Bob Clement'
SELECT MIN("First elected") FROM "table_18166" WHERE "Incumbent" = 'Bob Clement'