$chunk  = 4;

$arr    = array('1', '1', '1', '1', '1', '1', '1', '0', '1', '0', '1', '0', '0', '0', '0', '1');

1110
1101
1110
1001

there are 4 number '1' in first column, so the output should be 4

function array_chunk_vertical($arr, $percolnum){
$n = count($arr);
$mod    = $n % $percolnum;
$cols   = floor($n / $percolnum);
$mod ? $cols++ : null ;
$re     = array();
for($col = 0; $col < $cols; $col++){
    for($row = 0; $row < $percolnum; $row++){
        if($arr){
            $re[$row][]   = array_shift($arr);
        }
    }
}
return $re;
}

$result = array_chunk_vertical($arr, $chunk);
$new    = 0;
$exist  = 0;

foreach($result  as $row){
    foreach($row as $val){
        if($val == "1"){
            $new++;
        }
        else{
            $exist++;
        }
            echo $val;
    }
    echo '<br/>';
}