Fig. 2.

Regression model building strategy

Note. “Intercept” = regression model intercept; “Slope” = Regression model coefficient for year; “Change in 2012” = additional regression model coefficient to model non-linear change in 2012; “LL” = log-likelihood; “AIC” = information coefficient; “BIC” = Bayesian information coefficient; “Mean” indicates a single population-level coefficient; “State” indicates separate coefficients for each state; “*LL” = statistically significant difference in nested models based on LL; “*AIC” = AIC improved in nested model; “*BIC” = BIC improved in nested model