Get frequency from dataset with repeated measurements over time - sas

Question

this is my problem: I have a dataset that has 10 measurements over time, something like this:
ID Expenditure Age
25 100 89
25 102 89
25 178 89
25 290 89
25 200 89
.
.
.
26 100 79
26 102 79
26 178 79
26 290 79
26 200 79
.
.
.
27 100 80
27 102 80
27 178 80
27 290 80
27 200 80
.
.
.
Now I want to obtain the frequency of age, so I did this:
proc freq data=Expenditure;
table Age / out= Age_freq outexpect sparse;
run;
Output:
Age Frequency Count Percent of total frequency
79 10 0.1
80 140 1.4
89 50 0.5
The problem is that this counts all rows, but doesn't take into account the repeated measurements per id. So I wanted to create a new colum with the actual frequencies like this:
data Age;
set Age_freq;
freq = Frequency Count /10;
run;
but I think sas doesn't recognize this 'Frequency Count' variable, can anybody gives me some insight on this?
thanks

Answer 1

You have to remove the duplicate records so that each ID had one record containing the age.
Solution: create a new table with the disticnt values of the ID and Age. then run the proc freq
Code:
I created a new table called Expenditure_ids that doesn't have any duplicate values for the ID & Age.
data Expenditure;
input ID Expenditure Age ;
datalines;
25 100 89
25 102 89
25 178 89
25 290 89
25 200 89
26 100 79
26 102 79
26 178 79
26 290 79
26 200 79
27 100 80
27 102 80
27 178 80
27 290 80
27 200 80
28 100 80
28 102 80
28 178 80
28 290 80
28 200 80
;
run;
proc sql;
create table Expenditure_ids as
select distinct ID, Age from Expenditure ;
quit;
proc freq data=Expenditure_ids;
table Age / out= Age_freq outexpect sparse;
run;
Output:
Age=79 COUNT=1 PERCENT=25
Age=80 COUNT=2 PERCENT=50
Age=89 COUNT=1 PERCENT=25