Romania is a developing country, with a high-income economy, ranking 49th in the Human Development Index. It has the world's 45th largest economy by nominal GDP. Romania experienced rapid economic growth in the early 2000s; its economy is now based predominantly on services. It is a producer and net exporter of machines and electric energy through companies such as Automobile Dacia and OMV Petrom. Romania has been a member of the United Nations since 1955, NATO since 2004, and the European Union since 2007. The majority of Romania's population are ethnic Romanian and Eastern Orthodox Christians, speaking Romanian, a Romance language.