foreach $cat ( keys %data ) {
    foreach $date ( keys %{ $data{$cat} }) {
        print "<tr>";
    	foreach $data_type (sort { $a cmp $b } keys %{ $data{$cat}{$date} } ) {
    		print "<td align='left'>$data{$cat}{$date}{$data_type}</td>";
    		#print "<br>";
    	}
    	print "</tr>";
    }
    
}