Methods, apparatus, and articles of manufacture are disclosed. An example apparatus includes a co-viewing calculator to calculate a co-viewing factor corresponding to a demographic of panelists based on exposure information, an exposure time calculator to calculate a number of census co-viewer exposure minutes based on the co-viewing factor, a data aggregator to determine an aggregate exposure time total based on census exposure information and the number of census co-viewer exposure minutes, and a report generator to generate a report including the aggregate exposure time total.