Living conditions of the UN member countries
The best way to start your research is to visit the United Nations Statistics Division site at http://unstats.un.org/unsd/default.htm . It provides a lot of useful information, statistical databases and links to national statistical sources.
The United Nations Economic Commission for Europe (UNECE) ( http://www.unece.org/stats/data.htm ) provides statistics on European and North American countries.
You can also contact the Library of Parliament, the official depository for the publications of the UN ( http://www.eduskunta.fi/kirjasto/Welcome-eng.html ) or the United Nations University, WIDER ( http://www.wider.unu.edu ) in Helsinki. Their library focuses on developing countries, but they also provide the official statistics of the UN.