data statepop;
   input State $ citypop_80 citypop_90 
         Noncitypop_80 Noncitypop_90 Region @@;
   label citypop_80='1980 metropolitan pop in millions'
         noncitypop_80='1980 nonmetropolitan pop in millions'
         citypop_90='1990 metropolitan pop in millions'
         noncitypop_90='1990 nonmetropolitan pop in million'
         region='Geographic region';
    datalines;
ME   .405   .443  .721  .785 1   
NH  .535   .659  .386  .450  1
NY 16.144 16.515 1.414 1.475 1   
NJ 7.365  7.730   2.25 1.75   1
PA 10.067 10.083 1.798 1.799 1   
DE  .496   .553  .098  .113  2
IA  1.198  1.200 1.716 1.577 3   
MO 3.314  3.491 1.603 1.626 3
MT   .189   .191  .598  .608 4   
ID  .257   .296  .687  .711 4
HI   .763   .836  2.02  .272 4
;
proc univariate data=statepop;
   var citypop_90 citypop_80;
   title '800:121 practice: US Census of Population and Housing';
run;