The industrialized nations as usual were in the top 20, their ratings close to one another. Belgium was in sixth place, followed by Iceland, the United States, Japan, Ireland, Switzerland, Britain, Finland, Austria, Luxembourg, France, Denmark, New Zealand, Germany and Spain. . At the bottom of the list for the seventh year was Sierra Leone, emerging from a decade of civil war. Right above it were Niger, Burkina Faso, Mali and Burundi. . The worldýs newest nation, East Timor, was included for the first time and ranked 158th out of 177 countries. . In Africa, the AIDS crisis reduced the average life expectancy in many countries to 40 years or less, making it the biggest factor in the decline of overall human development indicators, the report said. In comparison, the average life expectancy in Norway was 79 years. . At least 20 nations suffered development reversals since 1990, 13 of them in Africa: Angola, Central African Republic, Lesotho, Mozambique, Sierra Leone, Swaziland, Zambia and Zimbabwe, the report said. . ýýThe AIDS crisis cripples states at all levels because the disease attacks people in their most productive years,ýý said Mark Malloch Brown, head of U.N. Development Program. . .