TABLE 2.

Summary of the best model with the lowest AIC value for predicting HA subtype diversity

Model	AIC value estimate	SE	z value	Pr (>|z|)a	Pb
Intercept	0.935	0.0696	13.433	<2e-16	****
Health care spending per capita in 2010	0.205	0.0405	5.074	3.89e-07	****
Gross domestic product in 2010	−0.0863	0.0320	−2.693	0.00709	***
Pig population density per square kilometer in 2010	0.0533	0.0290	1.84	0.06573	*
Growth rate of health care spending from 1995 to 2010	−0.237	0.103	−2.305	0.02115	**
Growth rate of pig population density from 1961 to 2010	−0.114	0.0734	−1.558	0.1192	*
Loge of no. of strains reported	0.643	0.0715	9.004	<2e-16	****

^aPr (>|z|), probability that the z value is greater than the estimate.

^b*, P < 0.10; **, P < 0.05; ***, P < 0.01; ****, P < 0.001.