Lithuania is a developed country, with a high income advanced economy; ranking very high in the Human Development Index. It ranks favourably in terms of civil liberties, press freedom and internet freedom. Lithuania has experienced a gradual population decline since the 1990s, with social issues such as income inequality and high suicide rate remaining a problem. Lithuania is a member of the European Union, the Council of Europe, eurozone, the Nordic Investment Bank, Schengen Agreement, NATO and OECD. It participates in the Nordic-Baltic Eight (NB8) regional co-operation format.