Table 5. The adjusted fitting and predictive R ², Ljung-Box Q statistics and p values of three models.

Model	1971–1993						1994–2012
	Fitting			Predictive			Fitting			Predictive
	adjusted R 2	Q	P	adjusted R 2	Q	P	adjusted R 2	Q	P	adjusted R 2	Q	P
GLM	0.997	25.690	4.001×10–7	0.752	0.670	0.413	0.984	1.480	0.224	0.669	2.424	0.120
GAM	0.959	0.099	0.753	0.799	3.712	0.054	0.818	0.258	0.611	0.756	2.358	0.125
PCRM	0.468	9.533	0.002	0.665	1.727	0.189	0.525	2.399	0.121	0.574	3.199	0.074

GLM: generalized linear model.

GAM: generalized additive model.

PCRM: principal component regression model.

Q: Ljung-Box Q statist.