[People watch the sun set from Lycabettus Hill in Athens]By Marc Jones LONDON (Reuters) - Greece's debt crisis has made its population the unhappiest not only in western Europe but also in comparison with people in some former Communist countries, a study showed on Tuesday. The "Life in Transition" survey conducted by the European Bank for Reconstruction and Development (EBRD) and the World Bank has questioned households across a broad region since 1991 as the Cold War came to an end, but Greece was included for the first time this year. Over 92 percent of Greeks said the debt crisis had affected them, with 76 percent of households suffering reduced income due to wage or pension cuts, job losses, delayed or suspended pay or fewer working hours.