Military service is voluntary, with enlistment age between 18 and 24 years old and no conscription.[163] Argentina's defense has historically been one of the best equipped in the region, even managing its own weapon research facilities, shipyards, ordnance, tank and plane factories.[164] However, real military expenditures declined steadily after 1981 and the defense budget in 2011 was about 0.74% of GDP, a historical minimum,[165] below the Latin American average.