如何使用php在相同（分组）元素/项的最后一行之后显示小计值

$stmt = mysqli_query($connection, $sql);

if($stmt === false) {
  die( print_r( mysqli_errors(), true) );
}

$category1 = 0;
$category2 = 0;
$category3 = 0;
$category4 = 0;
$category5 = 0;
$category6 = 0;
$category7 = 0;
$category8 = 0;

while($row = mysqli_fetch_array($stmt)) {

   if(strcasecmp($row['fruit_name'], 'apple') == 0) {
         $category1++;
   }
   if(strcasecmp($row['fruit_name'], 'banana') == 0) {
         $category2++;
   }
   if(strcasecmp($row['fruit_name'], 'cherry') == 0) {
         $category3++;
   }   
   if(strcasecmp($row['fruit_name'], 'dragon fruit') == 0) {
         $category4++;
   } 
   if(strcasecmp($row['fruit_name'], 'eastern hawthorn') == 0) {
         $category5++;
   } 
   if(strcasecmp($row['fruit_name'], 'finger lime') == 0) {
         $category6++;
   } 

   $sum = $row['total_fruit'] + $sum;

   $output .= '<tr>
             <td>' . $row['fruit_name'] . '</td>
             <td align=center>' .$row['total_fruit'] . '</td>
            </tr>';       
}
$output .= '<tr><td>$sum</td></tr></table>';

echo $output;

From the code above, I have calculated the sum of all rows(sum of fruits) and display it outside the while loop. I have 6 different fruits name that needs to be counted right after the last row of each same fruit. For example:

Fruit name   Total Fruit
________________________
Apple        1
Apple        1
Apple        1
------------------------
Subtotal     3
------------------------
Banana       1
Banana       1
------------------------
Subtotal     2
------------------------
.
.
.
Total       $sum

What I want to do is to display the subtotal of the same elements in the last row of each category