Colombia: 1964, 1973, 1985, 1993
France: 1962, 1968, 1975, 1982, 1990
Kenya: 1989, 1999
Mexico: 1960, 1970, 1990, 2000
United States: 1960, 1970, 1980, 1990
Vietnam: 1989, 1999

All persons.

PERWT indicates the number of persons in the actual population represented by the person in the sample. NOTE: PERWT has 4 implied decimal places.

PERWT is available for all samples, but only some samples have weights that differ from one person to another (i.e., some of the samples are "flat" samples in which the use of weights is optional).

The samples for which weights must be used to generate representative statistics are Colombia 1985, Mexico 2000, United States 1990, Vietnam 1989, and Vietnam 1999.

For the other samples a weight was calculated from the sampling fraction (but see the discussion for the United States). In those samples PERWT may not yield a precise count of the actual population to the extent that the theoretical sampling fraction was imperfect.

The Vietnamese samples use fractional weights (to four decimal places). All other samples use only whole numbers (the first 4 digits of PERWT).

The weight varies within households in 1990. In other years, PERWT gives the number of persons in the population represented by the sampled person (approximately equal to the sample density).

In 1989, men and women have separate weights. The weights are identical for all persons of that sex within a given enumeration area. The Vietnamese samples have fractional weights requiring the use of the decimal digits of PERWT.