Substract value in dataset and create proc reports

[Palucci]

I have a result table where there will always be two dates, I would like to subtract hip and not from each other, which is the more recent date than the previous one, and make a diffrence row with the difference. Unfortunately, I don't know how

my input :

hip	date	ubez
124545	2021-09-30	119348
123981	2021-10-31	119419

expect output

	hip	date	ubez
	124545	2021-09-30	119348
	123981	2021-10-31	119419
Diffrence	564		-71

[PaigeMiller]

That's the whole problem: a data set with two rows? Or is this a more general problem where you have lots of rows, paired into groups of two?

[Palucci]

data set with two lines, always subtracting the current

[PaigeMiller]

data have;
input hip	date :yymmdd10.	ubez;
cards; 
124545	2021-09-30	119348	 
123981	2021-10-31	119419	
; 

data want;
    set have end=eof;
    prev_hip=lag(hip);
    prev_ubez=lag(ubez);
    prev_date=lag(date);
    output;
    if eof then do;
        if date<prev_date then do;
            hip=hip-prev_hip;
            ubez=ubez-prev_ubez;
        end;
        else do;
            hip=prev_hip-hip;
            ubez=prev_ubez-ubez;
        end;
        call missing(date);
        output;
    end;
    drop prev_: direction;
    format date yymmddd10.;
run;