PROC UNIVARIATE computes the univariate statistics for two variables, CityPop_80 and CityPop_90. As PROC UNIVARIATE sends each output object to the Output Delivery System, ODS writes the pertinent information for that output object to the trace record.
proc univariate data=statepop mu0=3.5;
   var citypop_90 citypop_80;
run;