Redshift distribution of the values of A_V inferred from the Balmer decrement in sources with detected Hα and Hβ lines. For sources with upper limits on Hβ we derived lower limits on A_V. On the left, we also report the median values of A_V for NLAGN (magenta), non-AGN (cyan) and for the global population (black) in four different redshift bins. Errors are derived using the bootstrap procedure. On the right, we report the histogram of the A_V distribution for AGN (red) and non-AGN (blue).