Cesarean rate data available from CDC National Center on Health Statistics online: https://www.cdc.gov/nchs/nvss/births.htm
References:
Belfort, M.A. Placenta accreta. Am J Obstet Gynecol 2010; 203:430-439.
Placenta accreta. Committee Opinion No. 529. American College of Obstetricians and Gynecologists. Obstet Gynecol 2012;120:207–11.