CAKEPHP - 与Paginate设置的SUM

How can I make this work? Or is this possible? I want to add a row just for the total with pagination. I am new to Developing.. Hope you can help me with this problem.. Thanks..

Here is Paginate Function in Model

public function generateSettingsForPager($transportId, $year){
    $conditions['delete_flag'] = 0;

    if($transportId){
        $conditions['transport_id'] = $transportId;
    }

    if($year){
        $conditions['year'] = $year;
    }

    $settings = array (
        'fields' => 'id, year, transport_id, item, description, currency, budget, exchange_rate, all_in_php',
        'limit' => 30,
        'recursive' => -1,
        'order' => array(
            'id' => 'desc'
        ),
        'conditions' => $conditions
    );

    return $settings;
}

My index function in Controller

public function index(){

$getData = $this->request->query;
$transportId  = isset($getData['transport_id']) ? $getData['transport_id'] : null;
$year = isset($getData['year']) ? $getData['year'] : null;

$this->paginate = $this->UpgradingAndModification->generateSettingsForPager($transportId, $year);
$upgradingAndModifications = $this->paginate('UpgradingAndModification');

$this->set('transportId', $transportId);
$this->set('year', $year);
$this->set('upgradingAndModifications', $upgradingAndModifications);

}

This should be the index view.. See screenshot..

http://awesomescreenshot.com/0b94avre47

What I got so far is same with that screenshot but no Total yet.

Try This:

SUM(col1+col2) as total

In paginate settings

 public function generateSettingsForPager($transportId, $year){
    $conditions['delete_flag'] = 0;

    if($transportId){
        $conditions['transport_id'] = $transportId;
    }

    if($year){
        $conditions['year'] = $year;
    }

    $settings = array (
        'fields' => 'id, year, transport_id, item, description, currency, budget, exchange_rate, SUM(col1+col2) as total',
        'limit' => 30,
        'recursive' => -1,
        'order' => array(
            'id' => 'desc'
        ),
        'conditions' => $conditions
    );

    return $settings;
}