data work.np_combine;
set pg2.np_2015 pg2.np_2016;
CampTotal=sum(of Camping:);
where Month in(6, 7, 8) and ParkCode='ACAD' and Year=2016;
format CampTotal comma15.;
drop Camping:;
run;
ods select extremeobs;
proc univariate data=work.np_combine nextrobs=1;
var CampTotal;
id ParkCode Month Year;
run;