Histogram, subdivided into source types, showing the percentage of INTEGRAL objects of known nature in the fourth IBIS survey (Bird et al. 2010; open columns) and of INTEGRAL sources from various surveys and identified through optical or NIR spectroscopy at the time of acceptance of papers VII (November 2008; horizontally dashed columns), VIII (May 2010; vertically dashed columns), and IX (December 2011; diagonally dashed columns) along with those in the present one (filled columns).