Table 1.

The ADF test results of original monthly electric energy production data and its secondary differential data in Xinjiang.

			t-Statistic	p-value
Original data	Augmented Dickey–Fuller test statistic		1.98	0.9999
	Test critical values	1% level	− 3.46
		5% level	− 2.87
		10% level	− 2.57
Data after difference	Augmented Dickey–Fuller test statistic		− 13.48	< 0.001
	Test critical values	1% level	− 3.46
		5% level	− 2.87
		10% level	− 2.57