foreach $count ( sort keys %data ){
# there's a better notation for this but $data{$count}->@
# never works for my foreachs ;->
  foreach $type_hash ( @{ $data{$count} } ) {
    print "$count";
   # just to make it easier to see, loop through the keys
   # for the type hash in your order. NB type_hash is 
   # hash ref ($$type_hash)
    foreach $val ( (qw(type a_point z_point error) ) ) {
      print " --> $$type_hash{$val}";
    }           # foreach val
    print "\n";
  }             # foreach type_hash
}               # foreach count