I’m working with some 1980 data on black immigrants in counties in the Washington, DC metropolitan area. I was trying to create a count of the number of immigrants who identified their race as black, and initially the only option I saw was table NT004, Black Allocated In-Migrants by Country of Birth by Sex. I used this, but then realized I was looking at the wrong tables/wrong universe and needed the detailed breakout. I proceeded to download table NTPB25, Nativity and Place of Birth.
However, once I compared the values, I saw that for several counties, the values for NT004 were a lot larger than the values for NTPB25. How can the number of foreign born black in-migrants be larger than the value of TOTAL black immigrants living in the county?