Green Bay Press-Gazette - ‘Citizen’ has nice ring to it — Number of people who became naturalized U.S. citizens during fiscal 2002. The Fourth of July is a popular day for swearing in new U.S. citizens. Mexico contributed the highest number of naturalized citizens, 76,531, followed by Vietnam, 36,835; India, 33,774; China, 32,018; and the Philippines, 30,487. Candidates for citizenship are given a list of 100 questions and answers to study. The actual test includes 10 of the questions and six must be answered correctly to pass.