Macro loop in SAS - passing value to condition

I'm a beginner in SAS and I am struggling a bit with the macro loop in SAS. The problem is illustrated by the code below. The task here is to create separate subsets and save them as libraries for later post-processing. Additionally I added graphs for visualization. I am operating on a huge database but for this post I create a sample at the beginning of the code for simplification.

However, it seems that the internal condition (IF ID = i ) doesn't filter out the data. Instead the internal loop creates empty tables (but with correct names: "SUB1", "SUB2", "SUB3") with a column (variabale) called "i".

DATA EXAMPLE;

INPUT ID DATE DDMMYY8. VALUE;
FORMAT DATE DDMMYY8.;
DATALINES;
1 01012011 100
1 01022011 400
1 01032011 678
2 01012011 678
2 01022011 333
2 01032011 333
3 01012011 733
3 01022011 899
3 01032011 999
;
%MACRO filter(number);
    %DO i=1 %TO &number;
        DATA SUB&i;
        SET WORK.EXAMPLE;
        IF ID = i;
        PROC SGPLOT DATA=SUB&i;
        reg x=DATE y=VALUE;
        RUN;
    %END;
%mend filter;

%filter(3);

If I manually copy and paste the part inside macro and manually change i to numbers 1 to 3 it creates correct graphs. What is wrong in this code? How can I pass the value from the DO statement inside the code?

I am using SAS Studio.