sub datafilla {
  for my $y (1..5){
    my $y_diff = ($f_mpy[$y] - $f_mpy[$y-1]) || 1;
    my $e_diff = ($f_mpe[$y] - $f_mpe[$y-1]);
    $popbyyer[$y] = $e_diff / $y_diff;
    $grand[$y] = $grand[$y-1] + ( ($e_diff<0) ? abs ($e_diff) : 0 );
  }
}