Variables	Total samples		The eastern		The middle		The western		The northeastern
Variables	t	P	t	P	t	P	t	P	t	P
PICC	−7.3377	0.0000	−3.0362	0.0012	−4.2318	0.0000	−2.7134	0.0033	−3.6394	0.0001
SER	−4.7082	0.0000	−5.4199	0.0000	−1.9976	0.0229	−1.3832	0.0833	−10.8534	0.0000
GOV	−10.1680	0.0000	−3.5787	0.0002	−5.0970	0.0000	−3.9621	0.0000	−2.2373	0.0126
PAT	−12.9745	0.0000	−8.8343	0.0000	−16.7027	0.0000	−3.3342	0.0004	−3.1944	0.0007
SERPAT*	−7.8908	0.0000	−7.0394	0.0000	−9.0692	0.0000	−10.0298	0.0000	−1.7816	0.0374
URB	19.6709	0.0000	−8.5526	0.0000	−4.8734	0.0000	−1.8515	0.0321	−2.3111	0.0104
INF	21.1320	0.0000	−6.4032	0.0000	−11.4580	0.0000	−4.5988	0.0000	−3.0578	0.0011
POP	11.6638	0.0000	12.4728	0.0000	−1.7933	0.0360	−2.8294	0.0023	−3.7508	0.0001
TRA	7.5349	0.0000	−3.6060	0.0000	−3.7585	0.0001	−4.0843	0.0000	−3.2908	0.0005