"Throughout the 1950s and 60s we averaged well over 80,000 infant baptisms per year. At the same time we averaged over 30,000 adult conversions. If we had maintained the birth/infant baptism rate we had then, by my calculations we would have approximately 1.1 million more members in the LCMS."
LCMS Demographics of Birth Control
Note this data: http://concordiatheology.org/2012/06/a-glimpse-into-the-past-and-future-of-the-lcms/