CREATE TABLE table_28928 ("District" CLOB, "Incumbent" CLOB, "Party" CLOB, "First elected" CLOB, "Result" CLOB, "Candidates" CLOB)

How many incumbents are there in Pennsylvania 5?
SELECT COUNT("Incumbent") FROM table_28928 WHERE "District" = 'Pennsylvania 5'
SELECT COUNT("Incumbent") FROM "table_28928" WHERE "District" = 'Pennsylvania 5'