survey – n. an activity in which many people are asked a question or a series of questions in order to gather information about what most people do or think about something

demographer – n. someone who studies changes, such as the number of births, deaths, marriages, and illnesses, that occur over a period of time in human populations

LGBT – n. short for lesbian, gay, bisexual, transgender and queer

frequently – adj. happening often

heterosexual – adj. sexually attracted to people of the opposite sex

concentration – n. a large amount of something in one place

tend – v. used to describe what often happens or what someone often does or is likely to do