Can i loop through datatable column object and add new row addition of +2

I am fetching data from mysqli table using ajax jquery and fill that in Datatable as row using column object , can i able to loop through that data which i get in response from server and then make a new row addition by X number which i define.

I had tried but with this code i got same rows repeated in X times loop runs but don't add any kind of increment in other row.

My PHP API THAT GET DATA FROM MYSQL

 if(isset($_POST['what_need']) AND $_POST['what_need'] == 'signup_getslabs'){

$getTotalcountry = $obj->getSlabSignup($_POST['placeid'],$_POST['range']);
    $return_ardr=array();

foreach ($getTotalcountry as $row){
    $same_city_per_kg = $row['wc_slabr_hkg'];
    $diff_city_per_kg = $row['dc_slabr_hkg'];
    $fnfsamecityperkg = $same_city_per_kg-50;
    $fnfdifferentcityperkg = $diff_city_per_kg-50;
    $id = $row['id_slabr'];
for ($i = 3; $i >= 0; $i--) {
    $samecit =  $fnfsamecityperkg+50;
    $diffcit =  $fnfdifferentcityperkg+50;
     $return_ardr[] = array(
                    "samecity" => $samecit,
                    "diffcity" => $diffcit,
                    "weight" =>0.5,
                    "idslab" => $id
                    );
}
}




function utf8ize($d) {
    if (is_array($d)) {
        foreach ($d as $k => $v) {
            $d[$k] = utf8ize($v);
        }
    } else if (is_string ($d)) {
        return utf8_encode($d);
    }
    return $d;
}

echo json_encode(utf8ize($return_ardr));



}

MY DATATABLE CODE THAT SEND AJAX REQUEST TO API AND PRINT DATA IN TABLE DEFINED BY ID

$('#ratestd').DataTable( {
         "bDestroy": true,


         "serverSide": false,

         "ajax": {
            "url": "ajax-requests/ajaxm.php",
            "type": "POST",
            "dataSrc": function (d) {
         return d
      },
            "dataType": "json", 
            "data": function(data) {
        data.what_need = 'signup_getslabs';
        data.placeid = placeid;
        data.range = range;

        }

        },
        dom: 'Bflrtip',
         "buttons": [
    'copyHtml5', 'excelHtml5', 'pdfHtml5', 'csvHtml5','colvis'
  ],
        "columns": [
            { "data": "weight" },
            { "data": "samecity" },
            { "data": "diffcity" }
        ]


    });

I Expect output like this

WEIGHT SAMECITY DIFFERENT CITY 0.5 KG 50 100 1.0 KG 100 150 1.5 KG 150 200 2.0 KG 200 250

Expected Output

But What i get is

WEIGHT SAMECITY DIFFERENT CITY 0.5 KG 50 100 0.5 KG 50 100 0.5 KG 50 100 0.5 KG 50 100

What i Get

via Chebli Mohamed