Census tracts show about 66,000 houses in the center city.

New Jersey has about 1,900 census tracts, with an average of 4,000 people each.

A neighborhood was defined as a census tract, or 4,000 to 6,000 people.

The neighborhood areas are composed of and based on census tracts.

British census tracts were first developed in the city of Oxford.

Density was calculated using the land area and total population for each census tract.

Then the system can zero in on a mere neighborhood, or even a census tract, and give the same information.

Indeed, nearly 90 percent of the housing units in the census tract are rental.

But it wasn't poor: the poverty rate in Ken's census tract, 10 percent, was 2 points below the national average.

Today, every census tract in the city qualifies for federal poverty programs.