Show amount of results for exposed filter Drupal 7

mymodule.php

function mymodule_form_alter(&$form, &$form_state, $form_id) {
switch($form_id){
case 'views_exposed_form':

  foreach ($form['field_marka_prochnosti_tid']['#options'] as $tid => &$value) {
    $query = db_select('field_data_field_marka_prochnosti', 'f')
            ->condition('f.field_marka_prochnosti_tid', $tid);
    $query->addExpression('COUNT(*)');
    $count = $query->execute()->fetchField();
    $value = $value . ' (' . $count . ')';
  }

  break;
  }
}