Fig. 3

Homicide trends for municipalities with population less than 25 thousand clustered into four groups using principal component cluster analysis. Each curve represents the average trend within each cluster. Each cluster contains the following number of municipalities: A. 1765 (42.1%), B. 554 (13.2%), C. 1177 (28.1%) and D. 695 (16.6%). The overall trend suggests an increase in homicide rates, which supports our study hypothesis that homicide rates have increased in municipalities with smaller populations