Notes
The stratification used in the sample design defines the basic geographic units within which the sample was designed. For example, if the sample was designed to be self-weighting within region, this variable would define those regions; if the sample was designed to be selfweighting within major urban areas, other urban areas and rural areas, this variable would define the major urban, other urban and rural areas. If the sample is self-weighted at the national level, this variable is code 0.