What does "demographics of victimization" mean

Victim Selection Types

Serial killers usually pursue a particular type of victim. Analyzing the characteristics of a killer's victims can greatly assist the effort to create a typology of the killer.
•What does "demographics of victimization" mean? How can location relate to the demographics of victimization?
•Do serial killers with different typologies use the same methods for victim selection?
•How are the methods used for victim selection by serial killers similar to or different from the methods used by a mass murderer?
•Consider any of these killers: Aileen Wuornos, Ted Bundy, or Wayne Williams. Discuss how their choice of victims related to their typology. If you were an investigator working on this case, how would you use the victims' characteristics to assist in the investigation?