sub printdata{
              foreach (sort keys %list){ #! CHANGED 
				  	  $cust = $_;        #! ADDED
                      $total = $list{$cust}->{new} - $list{$cust}->{prior};
                      write;
                      }
              }
__DATA__
"fred", 10
"barney", 30
"Bam bam", 5
"Wilma", 200
"Betty", 300
# Output
+-----------------------------------------------------------------+
|                           Monthly Recap                         |
|----------------------------+----------+-----------+-------------+
|Account                     | Prior    | Current   | Difference  |
|----------------------------+----------+-----------+-------------+
|Bam bam                     |     5.00 |     10.00 |      5.00   |
|----------------------------+----------+-----------+-------------+
|Betty                       |   300.00 |     10.00 |   -290.00   |
|----------------------------+----------+-----------+-------------+
|Wilma                       |   200.00 |     10.00 |   -190.00   |
|----------------------------+----------+-----------+-------------+
|barney                      |    30.00 |     10.00 |    -20.00   |
|----------------------------+----------+-----------+-------------+
|fred                        |    10.00 |     10.00 |      0.00   |
|----------------------------+----------+-----------+-------------+