I am using the 1990 Block-level total population data of Alabama.
In the block-level GIS file (1990, basis: 2000 TIGER/Line +), there are 173,147 features.
However, the source table has 111,868 block-level observations.
Is anyone else seeing the same problem? Could anyone help explain the discrepancy?
Edit:
I further checked the number of features at the block-level for Alabama in subsequent decennial years.
In 2000:
The source table has 175,220 observations.
The GIS shapefile (basis: [2000 TIGER/Line +]) has 175,118 features.
In 2010:
The source table has 252,266 observations.
The GIS shapefile (basis: [2010 TIGER/Line +]) has 251,720 features.
In 2020:
The source table has 185,976 observations.
The GIS shapefile (basis: [2020 TIGER/Line +]) has 185,741 features.
There is still a gap in feature count for 2020, 2010 and 2000, although the gap is smaller. The biggest gap is for 2000.