Table 5

Time	Independent variable	Unstd. coefficients		t-statistic	P-value	r²
Time	Independent variable	β	SE	t-statistic	P-value	r²
Baseline	Constant	5.28	1.017	5.189	< 0.001^a	0.23
Baseline	RAL	-0.282	0.098	-2.88	0.008^a	0.23
9 months	Constant	4.746	0.163	29.178	< 0.001^a	0.27
9 months	Defect fill	0.016	0.005	3.465	0.002^a	0.27

^aStatistically significant at P < 0.001 (stepwise multiple linear regression analysis).
β = beta coefficient; SE = standard error; r² = coefficient of determination.