my %seen = (); 

foreach my $line (@lines) {
    my @values = split ',', $line;

    my $col1_val = $values[0];
    my $key = $values[2];
    my $true_or_false = $values[7];
    
    $key =~ /^LOGGED IN (\w+) GET/;
    $key = $1;
    
    $seen{$key}->{num_false}++ if $true_or_false eq 'false';
    push @{$seen{$key}->{col1_vals}}, $col1_val;
}

foreach my $key (keys %seen) {
    my $calcd = calculate_stuff($seen{$key}->{col1_vals});
    my $num_false = $seen{$key}->{num_false};

    print <<HERE;
Key:           $key
Calc'd values: $calcd
Num false:     $num_false
HERE
}