sub popnum3 {
    use Data::Dumper;
    my ( $x, $y, $z ) = @_;
    my @row  = eval{@{$aob[ $y - 1 ]}} or die "$x\n$y\n$z\n", Dumper $aob[ $y - 1 ];
    my $mean = mean(@row);
    $aob[$x][$y] = $mean * ( 1 + $z );
    return $aob[$x][$y];
}