The armed forces have three branches: Navy, Army and Air Force. They serve primarily as a self-defense force whose mission is to protect the territorial integrity of the country and provide humanitarian assistance and security at home and abroad. , the three branches numbered 39,200 active personnel including 7,500 women. Portuguese military expenditure in 2009 was 5 billion US$, representing 2.1 per cent of GDP. Military conscription was abolished in 2004. The minimum age for voluntary recruitment is 18 years.