CREATE TABLE table_16765 ("Race Name" TEXT, "Circuit" TEXT, "Date" TEXT, "Winning driver" TEXT, "Constructor" TEXT, "Report" TEXT)

How many different kinds of reports are there for races that Juan Manuel Fangio won?
SELECT COUNT("Report") FROM table_16765 WHERE "Winning driver" = 'Juan Manuel Fangio'
SELECT COUNT("Report") FROM "table_16765" WHERE "Winning driver" = 'Juan Manuel Fangio'