SEASON OF BIRTH AND MENTAL DEFICIENCY.
D001699:Biometry; D004314:Down Syndrome; D005260:Female; D006801:Humans; D008607:Intellectual Disability; D036801:Parturition; D012621:Seasons; D013223:Statistics as Topic; D013548:Sweden; D014798:Vital Statistics
MENTAL RETARDATION; MONGOLISM; SEASONS; STATISTICS; SWEDEN; VITAL STATISTICS