Produce the block maps. The FORMAT statements assign POPFMT. to the POP variable and $REGIONFMT. to the REGION variable. The AREA statement assigns patterns to the map areas according to the values of the REGION variable. The RELZERO option specifies that the blocks values are relative to zero.

proc gmap data=sashelp.demographics(where=(cont=95))
          map=maps.asia all;
   format pop popfmt.;
   format region $regionfmt.;
   id id;
   area region / midpoints="SEAR" "EUR" "EMR" "WPR";
   block pop / levels=all
               legend=legend1
               relzero;
run;
quit;