Table 15.

$R^2$ improvements for CO, NO2, PM10, LR, ANN, RF, by months in 2019.

Pollutant	${\mathit{R}}^2 \mathrm{Improvement}$
	February	April	August	October
CO	0.035	0.025	0.066	0.022
NO2	0.120	0.097	0.146	0.086
PM10	0.051	0.042	0.067	0.038