use Data::Dump qw(dump);
print "x_data: ", dump($keyed_list->{chart}->{series}->{"x-data"}), "\n";
print "y_data: ", dump($keyed_list->{chart}->{series}->{"y-data"}), "\n";

# which outputs
#x_data: [1, 2, 3, 4, 5]
#y_data: [20, 90, 60, 50, 30]