Table 2. Linear regression model for each syphilis time series removed seasonality.

	Constant	Coefficient	Coefficient 95% confidence Interval		R2	P
Primary syphilis	0.28232	0.00473	0.00442	0.00504	0.908	0.002
Secondary syphilis	0.21493	0.00237	0.00219	0.00255	0.872	<0.001
Tertiary syphilis	0.00550	0.00015	0.00014	0.00016	0.903	<0.001
Latent syphilis	0.16333	0.01390	0.01329	0.01451	0.955	0.007
Congenital syphilis	0.02824	0.00055	0.00050	0.00060	0.848	<0.001

Note: The linear relationship between the deseasonalized syphilis incidence (dependent variable) and time t (independent variable) is estimated in the model.