Rounding

 

These data will not add up to the available via SF3 due to special tabulation rounding rules that were not used for SF3.  The rounding rules applied to each cell are as follows:

 

0 rounds to 0

1-7 rounds to 4

all other values round to the nearest multiple of 5

 

Each table has a cell labeled "total".  That cell reflects the unrounded total of all of the other cells that is then rounded according to the rules above.  As such, summing the rounded cells will not equal this "total" column.  The purpose of the "total" column is to give the user some information on the extent to which rounding is overly inflating or deflating the unrounded totals for the cells.

 

HUD analysis of the rounding shows that tables with more cells (such as a large table at the Census Tract geography) when aggregated to the national level results in a national deflation of total population.  However, for individual places and counties, sometimes it inflates or deflates. For this reason, we suggest that users work with the tables at the highest level of geography for their particular project.  We also suggest that users be careful when comparing differences with the 1990 Census data and when comparing the data across tables or with the SF3 standard tabulation data.

 

Suppression

 

A few tables are subject to data suppression.  These tables are the F3 and F4 series of tables for Native Americans and the F6 and A7 tables on elderly households.

 

The specific suppression rules are noted in the documentation for those tables.  Generally, if suppression has been applied to a specific cell, the cell is filled with a -1.  If there is a zero in a table with suppression, that means that the value is zero.