Table 4. Unit root test results for each variable.

Variable	Statistical Quantities		Result
	LLC Inspection	IPS Inspection
FW	-5.3198***	-3.5802***	stable
HLW	-10.4344***	-11.2039***	stable
ZD	-5.3119***	-6.7673***	stable
RL	-7.4215***	-4.1042***	stable
RK	-6.7735***	-2.2535**	stable
CZ	-7.6396***	-180***	stable
MD	-15.1784***	-13.6366***	stable
ZZ	-5.1749***	-83.5420*	stable
RJ	-7.0635***	-8.2809***	stable

Note

*, **, *** indicate statistical results are significant at the 10%, 5% and 1% confidence levels, respectively.