#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;

my @set = (
    {
        'id' => '1462',
        'items' => [ '9.9', '10.1', '10.3', '10.5', '10.8', '10.94' ],
    },
    {
        'id' => '1463',
        'items' => [ '3.1', '4.3', '4.5', '4.6', '4.7', '4.8' ],
    }
);

my @totals;
for my $href ( @set ) {
    $totals[ $_ ] += $href->{items}[ $_ ] for 0 .. $#{ $href->{items} };
}

print Dumper \@totals;
__END__
C:\test>540833
$VAR1 = [
          '13',
          '14.4',
          '14.8',
          '15.1',
          '15.5',
          '15.74'
        ];