blockid  = block ID number              
ccid = ID of the connected component the block belongs to
pmsa = ID of the MSA the block belongs to

littlesi = block SSI
ccsi = connected-component SSI

whitemsa_si=white segregation index at the msa level
blackmsa_si=black segregation index at the msa level
asianmsa_si=asian segregation index at the msa level
hispmsa_si=hispanic segregation index at the msa level

race : 1=white, 2=black, 3=asian, 4=hispanic

blocksi         double %10.0g                 

lat             float  %9.0g                  
lng             float  %9.0g                  
pop             int    %8.0g                  
white           int    %8.0g                  
black           int    %8.0g                  
asian           int    %8.0g                  
hisp            int    %8.0g     

pctwhite        float  %9.0g                  
pctblack        float  %9.0g                  
pctasian        float  %9.0g                  
pcthisp         float  %9.0g                  

maxrace         float  %9.0g                  
size            float  %9.0g