how do i construct a sas do loop to get the amount of what's left to be paid?

hope you can help me.

The below table wants to show the result I want to get by using a sas code. Basically, it's about calculating the amount of an installment, starting from par_value of 10.000€, with 6% interest rate for 10 years, paying a fixed installment at the end of each period.

interests is obtained by multiplying the 6% interest rate per the par_value;

capital_paid is the difference between the installment and the interest paid for a given year.

loan_paid is the sum of the parts of the capital each year that got paid.

to_be_paid is the difference between the capital to pay at given year minus the capital_paid (the value of the first year in the first row is 10000-1358,68).

What did you tried?

I can propose something like this:

data test;
    attrib year par_value fixed_installment interest_rate interest capital_paid loan_paid to_be_paid format=best.;
    
    *-- Initial values --*;
    par_value = 10000;  
    fixed_installment = 1358.68;
    interest_rate = 0.06;
    loan_paid = 0;
    
    *-- Loop through 10 years --*;
    do year = 1 to 10;
        *-- Calculate interests --*;
        interest = round((par_value - loan_paid) * interest_rate, 0.01);
        
        *-- Calculate capital paid --*;
        capital_paid = fixed_installment - interest;
        
        *-- Calculate loan paid --*;
        loan_paid = loan_paid + capital_paid;
        
        *-- Calculate remaining loan --*;
        to_be_paid = par_value - loan_paid;
        
        output;
    end;
run;