my @data = (
             [1,"info"],   
             [1,"info"],   
             [1,"info"],   
             [2,"info"],   
             [3,"info"],   
             [3,"info"],   
             [4,"info"],   
             [4,"info"],   
             [4,"info"],   
             [4,"info"],   
            );

##</code><code>##

my %freq = ();
foreach my $datum (@data) {
    $freq{ sprintf("%d    %s", @$datum) }++;
}

##</code><code>##

{
    local $,=$/;
    print sort { $freq{$b} <=> $freq{$a} } keys %freq;
}