Table 3.
Significance test

	Gangwondo	Gyeongsangdo	Jeollado	Jejudo
Density	0.882	0.860	0.872	0.927
Average bootstrap density	1.305	0.823	0.837	1.532
Estimated standard error for density	0.2525	0.1243	0.111	0.223
Z-score	5.0098	6.411	7.262	6.645
Proportion of absolute differences as large as observe	0.0002	0.0002	0.0002	0.0002