I have downloaded the table NT1A from the 1980 STF1. In this table it should be reported the population of every single 1980 census tract (and consequently of every county) in the US.
However, the total number of counties in the file is 1812 instead of more than 3000.
So for example Bibb county of Alabama (FIPS 01007) is not recorded in the dataset but is recorded to exist in these files from the Census Bureau (https://www.census.gov/data/tables/time-series/demo/popest/1980s-county.html). And, additionally the once I summed across the variable pop80 across every census tracts I obtained a total of 196 million when the world bank reports a total population of 226 million.
How should I proceed?