It's not germane to your problem, but you get prettier Data::Dumper output for hashes if you use references.

For example, given

use Data::Dumper;

my %hash = (
    9 => {
        11 => '54.9503577512828',
        21 => '40.4544882398113',
    },
    4 => {
        11 => '26.7647206436788',
        21 => '19.4128184125387',
    }
);
[download]

print Dumper %hash yields

$VAR1 = '4';
$VAR2 = {
          '11' => '26.7647206436788',
          '21' => '19.4128184125387'
        };
$VAR3 = '9';
$VAR4 = {
          '11' => '54.9503577512828',
          '21' => '40.4544882398113'
        };
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but print Dumper \%hash (note the backslash) produces

$VAR1 = {
          '4' => {
                   '11' => '26.7647206436788',
                   '21' => '19.4128184125387'
                 },
          '9' => {
                   '11' => '54.9503577512828',
                   '21' => '40.4544882398113'
                 }
        };
[download]