slum – n. an area where poor people live and the buildings are in bad condition

census – n. the official process of counting the number of people in a country, city, or town and collecting information about them

stability – n. the quality of being in a good state or condition that is not easily changed or likely to change

data – n. facts or information used usually to calculate, analyze, or plan something

statistician – n. a person who collects and studies statistics

vendor – n. a person who sells things, especially on the street

informal – adj. not according to the prescribed, official, or customary way or manner

address – n. the words and numbers that are used to describe the location of a home or building

code – n. a set of letters, numbers or symbols that identifies or gives information about something or someone