CREATE TABLE table_18155 ("District" CLOB, "Incumbent" CLOB, "Party" CLOB, "First elected" CLOB, "Results" CLOB, "Candidates" CLOB)

How many elections have resulted in retired democratic hold?
SELECT COUNT("Party") FROM table_18155 WHERE "Results" = 'Retired Democratic hold'
SELECT COUNT("Party") FROM "table_18155" WHERE "Results" = 'Retired Democratic hold'