Readme-Block-csv.txt

ftp://ftp.abag.ca.gov/pub/mtc/census2000/

This is the readme file for six data files representing the entire
Census 2000 PL 94-171 dataset for the San Francisco Bay Area. Data
is extracted for all census blocks in the Bay Area.

The data files on the FTP site are contained in "zipped" archive files.

All data files are suffixed with "csv" - - comma separated values, and
are intended for import into standard spreadsheet software. 

(The largest EXCEL worksheet can be 65,536 rows and 256 columns of data. 
The Bay Area PL 94-171 block level database represents 76,533 "rows" and 
over 288 "columns" of data.)

block_ebay12.zip unzips to block_ebay12.csv
block_ebay34.zip unzips to block_ebay34.csv
block_nbay12.zip unzips to block_nbay12.csv
block_nbay34.zip unzips to block_nbay34.csv
block_wbay12.zip unzips to block_wbay12.csv
block_wbay34.zip unzips to block_wbay34.csv

The "ebay" files are census blocks in the east bay: Alameda and Contra
Costa Counties. Total blocks = 25,273, including "water blocks."

The "nbay" files are census blocks in the north bay: Marin, Sonoma,
Napa and Solano Counties. Total blocks = 18,602, including "water blocks."

The "wbay" files are census blocks in the west bay / peninsula: San Francisco,
San Mateo and Santa Clara Counties. Total blocks = 32,658, including
"water blocks."

The "12" code represents PL 94-171 tables PL-1 and PL-2. These are the total
population by race and ethnicity tables.

The "34" code represents PL 94-171 tables PL-3 and PL-4. These are the total
population, AGE 18+, by race and ethnicity tables.

These "csv" files have variables names in the first record of each dataset.

The following is a brief description of the variables in these "csv" files.

sumlev  = summary level (750 is block level data)
lrn	    = logical record number (value used to join different PL data files)
state
county
place	= 5-digit FIPS code
tract
blkgrp	= block group
block
arealand= land area in square meters
areawatr= water area in square meters
name	= name of the block, e.g., "block 100"
pop100  = 100% population count, Census 2000
taz		= Census Transportation Planning Package (CTPP) Travel Analysis Zone (TAZ)
rtaz	= MTC Regional Travel Analysis Zones (1099 zone system)

Data cells for all four tables are named with the following convention:

t1c01-t1c71   Table 1, cell 1 through cell 71
t2c01-t1c73   Table 2, cell 1 through cell 73
t3c01-t3c71   Table 3, cell 1 through cell 71
t4c01-t4c73   Table 4, cell 1 through cell 73

To understand the definition of each of these 71 and 73 cell tables, the user must 
download the detailed PL 94-171 documentation from either the Census Bureau's 
web site, or this FTP site at: 

ftp://ftp.abag.ca.gov/pub/mtc/census2000/pl94-171.pdf

Direct comments or questions on this readme or the data files to Mr. Chuck Purvis
of MTC at (510) 464-7731, e-mail: cpurvis@mtc.ca.gov.

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