tokens: The overall prevalence of a major birth defect was 446.3 per 10,000 births ( 95 % CI : 444.0-448.6 ) ; 470.9 per 10,000 births ( 95 % CI : 467.6-474.2 ) for males and 420.2 per 10,000 births ( 95 % CI : 417-423.4 ) for females .