My input data is like this:

ID    Record  Time  A  B  C  D  E  F  G
A776  762.81  0.76  2  2  2  2  2  2  2
A872  762.91  1.23  4  4  4  4  4  4  4
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What my code does is to take A column and divide row against row, same for the rest of B to G. And the list continue down...(I have thousands of IDs). This process refer to this code as stated in my first post:

for my $arr_ref1 (@full_data)
    {        
            for my $arr_ref2(@full_data)
            {
            for my $index (3..$#headers)
                {
                 my $ratio1 = $$arr_ref2[$index]/$$arr_ref1[$index]; #
+ this is the part where 1 and 2 is outputted.
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I hope it helps in the understanding of my question?