CREATE TABLE table_21938 ("Round" TEXT, "Main date" TEXT, "Number of fixtures" FLOAT, "Clubs" TEXT, "New entries this round" TEXT, "Prize money" TEXT, "Player of the Round" TEXT)

How many categories of new entries this round are there for the fourth round proper?
SELECT COUNT("New entries this round") FROM table_21938 WHERE "Round" = 'Fourth Round Proper'
SELECT COUNT("New entries this round") FROM "table_21938" WHERE "Round" = 'Fourth Round Proper'