For defining a 'Census Town' (as opposed to a Statutory Town), the Census of India uses criteria including minimum population, minimum population density, and a certain percentage of the working population engaged in non-agricultural activities. While the numerical thresholds for population (5000) and density (400/sq km) have been relatively consistent, the exact definition or focus regarding the 'working population' criterion, particularly the percentage (typically 75%) and the specific group considered (e.g., male main working population), is the criterion that has seen minor variations or shifts in emphasis/definition across different censuses in recent decades compared to the others.