#!/usr/bin/perl

use 5.010;
use strict;
use warnings;
use Spreadsheet::WriteExcel;

my $WriteWorkbook = Spreadsheet::WriteExcel->new('Write.xls');
my $WriteWorksheet = $WriteWorkbook->add_worksheet('Data');
my $formula = $WriteWorksheet->store_formula('=1-(F1/E1)');
my $f_change = $WriteWorkbook->add_format();
$f_change->set_num_format('0.00%');

for my $row ( 1..4 ) {
  for my $col ( 4..5 ) {
    $WriteWorksheet->write($row, $col, rand());
  }
  $WriteWorksheet->repeat_formula($row, 13, $formula, $f_change, 'F1','F'.($row+1), 'E1', 'E'.($row+1));
}