Why are government census figures for the number of Witnesses higher than your figures?

[The Librarian]

Government census bureaus often determine their figures by asking people which religious group they identify themselves with. For example, the U.S. Census Bureau states that their surveys “sought to determine whether the respondents regarded themselves as adherents of a religious community,” adding that the resulting figures are “subjective rather than objective.” By contrast, we count as Jehovah’s Witnesses only those who preach to others and who report that activity, not those who merely identify themselves as Witnesses.