Year and Year.1 (columns 1 and 2): Year is the year for which the annual enrollment figures are taken. You will notice that year appears twice, in column 1 (as a factor) and then again in column 2 (integer). This is because the data has been previously preprocessed, and appears twice merely for convenience, since there are certain instances in which we will prefer to use a factor, and other instances in which we prefer to use an integer. The numbers in parentheses in Year refer to footnotes in the original data sources. Please refer the the reference notes at the CMS website for a full explanation of how the data was collected. While you could always create integers from factors and vice versa in the code, this saves valuable processing time if certain transformations can be made available beforehand.
Total people (column 3): Total people is the population size of the category. They may either enrolled for health coverage (total) or not (Not.Covered).
Total (column...
