CREATE TABLE table_72400 ("District" CLOB, "Incumbent" CLOB, "Party" CLOB, "First elected" CLOB, "Result" CLOB, "Candidates" CLOB)

How many times was incumbent Noble Jones Gregory first elected?
SELECT COUNT("First elected") FROM table_72400 WHERE "Incumbent" = 'Noble Jones Gregory'
SELECT COUNT("First elected") FROM "table_72400" WHERE "Incumbent" = 'Noble Jones Gregory'