“…Individual are classified in two groups: those having income from wages and pension only, on the one side, and those having income also from other sources. Portugal, Instituto Nacional de Estatística, Estatísticas das Receitas Fiscais, 1989-1995, 1997, 1998. Tabulations for 2001, 2002and 2003 were provided by the tax agency of Portugal, based on internal reports.…”