Try prefixing your value sets with zeros.

use GD::Graph::lines;

@data = (
    [ '0', "1st","2nd","3rd","4th","5th","6th","7th", "8th", "9th", ],
    [ 0, 1, 2, 5, 6, 3, 1.5, 1, 3, 4, ],
    [ 0, sort { $a <=> $b } (1, 2, 5, 6, 3, 1.5, 1, 3, 4) ],
);

my $graph = GD::Graph::lines->new(400,400);
$graph->set (
    x_label => 'values1',
    y_label => 'values2',
    title => 'Correlate',
) or die $!;

my $gd = $graph->plot(\@data) or die $!;

open (IMG, '>file.png') or die $!;
binmode IMG;
print IMG $gd->png;
close IMG;
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Also, please read the formatting guidelines next time you post.