/sci/ - Science & Math

>>9035135
not the guy, but here is a more recent statistic
from Macleod's Clinical examinations (2013 pp.229), used by Medical students in the UK

>>9033663
on the contrary you only need to have 30 pregnancies of 45-y.o mothers to have a down syndrome, whereas you need 1500 pregnancies at 20-y.o.,
i.e.:you don't need same numbers of cases to compare them.