31.   A federal official subsequently admitted that authorities might have underestimated the number of participants.

32.   But Links said he may have underestimated the number because he only surveyed people with telephones.

33.   But the data underestimates the number of girls involved in household work.

34.   Many independent experts challenge the official data, which they say vastly underestimates the number of AIDS sufferers and persons infected with HIV.