Complex sentence: The CDI rewards migration of both skilled and unskilled people, though unskilled more so, using data on the gross inflow of migrants from developing countries in a recent year and the net increase in the number of unskilled migrant residents from developing countries during the 1990s.
Split into simpler sentences: The CDI rewards migration of both skilled and unskilled people, though unskilled more so. It uses data on the gross inflow of migrants from developing countries in a recent year and the net increase in the number of unskilled migrant residents from developing countries during the 1990s.