Or 'Relational' like this perhaps

#!perl
use strict;    
use warnings;
use DBI;

#create db
my $dbfile = 'database.sqlite';
unlink($dbfile);
my $dbh = DBI->connect('dbi:SQLite:dbname='.$dbfile , undef , undef , 
                {RaiseError =>1, AutoCommit =>0}) or die $DBI::errstr;
$dbh->do('CREATE TABLE STATS (ID    integer,
                              DTIME time, 
                              PRIMARY KEY (ID))');
$dbh->do('CREATE TABLE SALES (ID integer,
                              PRODUCT, 
                              VOLUME integer, 
                              PRIMARY KEY (ID,PRODUCT))');
$dbh->do('CREATE TABLE PRODUCT (PRODUCT, 
                                SECTOR, 
                                PRIMARY KEY (PRODUCT))');
$dbh->commit;

# load data
my $sth = $dbh->prepare('INSERT INTO STATS VALUES (?,?)');
while (<DATA>){
  chomp;
  last if $_ eq 'PRODUCT';
  my ($id,@f) = split ',';
  my $dt = sprintf "%04d-%02d-%02d %02d:%02d:00",@f[2,1,0,3,4];
  $sth->execute($id,$dt) if ($id);
  print "STATS INSERT $id,$dt\n";
}
$dbh->commit;

$sth = $dbh->prepare('INSERT INTO PRODUCT VALUES (?,?)');
while (<DATA>){
  chomp;
  last if $_ eq 'SALES';
  my (@f) = split ',';
  $sth->execute(@f) if (@f==2 );
  print "PRODUCT INSERT @f\n";
}
$dbh->commit;

$sth = $dbh->prepare('INSERT INTO SALES VALUES (?,?,?)');
while (<DATA>){
  chomp;
  my (@f) = split ',';
  $sth->execute(@f) if (@f==3);
  print "SALES INSERT @f\n";
}
$dbh->commit;

# report Sales in Sector By Year
print "\n";

my $sql = "SELECT strftime('%Y',DTIME) as year,SECTOR,SUM(VOLUME) AS t
+otal 
           FROM SALES AS sa
           LEFT JOIN STATS AS st 
              ON sa.ID = st.ID
           LEFT JOIN PRODUCT AS pr 
              ON sa.PRODUCT = pr.PRODUCT   
           GROUP BY year,SECTOR
           ORDER BY total";           

my $ar = $dbh->selectall_arrayref($sql);

print "REPORT\n";
printf "%4s %-10s %6s\n",qw(Year Sector Volume);
printf "---- ---------- ------\n";
for (@$ar){
  printf "%4d %-10s %6d\n",@$_;
}

__DATA__
1,1,1,2000,4,44
2,1,1,2000,4,45
PRODUCT
burgers, food
fries, food
sodas, drink
SALES
1,burgers,5 
1,fries,3
1,sodas,11
2,burgers,2 
2,fries,4
2,sodas,7
[download]

Produces

REPORT
Year Sector     Volume
---- ---------- ------
2000  food          14
2000  drink         18
[download]

poj