Table 3. Results of stepwise multiple linear regression.

MCs	Fitting equation	Correlation coefficient R	Adjusted R2	Tolerance	VIF	Model fitting		Partial regression coefficient test	D–W statistic
						F	P
TMCs	y = 116.848 + 46.449χ3	0.581	0.337	1	1	44.792	<0.001	χ3(t = 6.693, P < 0.001)	1.979
	y = 805.526 + 42.979χ3 − 92.886χ2	0.716	0.513	0.989	1.001	45.87	<0.001	χ3(t = 7.148, P < 0.001)
								χ2(t = −5.608, P < 0.001)
	y = 538.069 + 35.557χ3 − 75.968χ2 + 6.452χ1	0.741	0.549	0.693	1.443	34.938	<0.001	χ3(t = 5.495, P < 0.001)
								χ2(t = −4.396, P < 0.001)
								χ1(t = 2.622, P = 0.01)
TMC-RR	y = 799.874 − 99.263χ2	0.718	0.515	1	1	93.396	<0.001	χ2(t = −9.664, P < 0.001)	1.828
	y = 825.53 − 101.047χ2 − 35.61χ4	0.738	0.544	0.994	1.006	51.98	<0.001	χ2(t = −10.066, P < 0.001)
								χ4(t = −2.375, P = 0.02)
	y = 676.095 − 91.169χ2 − 39.668χ4 + 3.42χ1	0.759	0.576	0.846	1.181	38.908	<0.001	χ2(t = −8.682, P < 0.001)
								χ4(t = −2.709, P < 0.001)
								χ1(t = 2.522, P = 0.014)
TMC-YR	y = 1.54 − 0.013χ7	0.268	0.072	1	1	6.83	0.011	χ3(t = −2.613, P = 0.011)	2.299
TMC-LR	y = 11.216 + 41.829χ3	0.806	0.650	1	1	163.585	<0.001	χ3(t = 12.79, P < 0.001)	1.461
	y = 63.349 + 32.481χ3 − 6.653χ6	0.848	0.718	0.678	1.476	111.004	<0.001	χ3(t = 9.06, P < 0.001)
								χ6(t = −4.592 P < 0.001)

Note:

The fitting result of TMC-YR after lg10 conversion; D–W statistic (Durbin–Watson statistic); Variance Inflation Factor (VIF).