I'm running the following code over a set of 5,000 results. It's failing due to the memory being exhausted.

foreach ($data as $key => $report) {
  $data[$key]['data'] = unserialize($report['serialized_values']);
}

I know I can up the memory limit, but I'd like to run this without a problem instead. I'm not going to be able to keep upping the memory forever.

EDIT

The $data is in this format:

[1] => Array
    (
        [0] => 127654619178790249
        [report_id] => 127654619178790249
        [1] => 1
        [user_id] => 1
        [2] => 2010-12-31 19:43:24
        [sent_on] => 2010-12-31 19:43:24
        [3] => 
        [fax_trans_id] => 
        [4] => 1234567890
        [fax_to_nums] => 1234567890
        [5] => ' long html string here',
        [html_content] => 'long html string here',
        [6] => 'serialization_string_here',
        [serialized_values] => 'serialization_string_here',
        [7] => 70
        [id] => 70
    )