East and Central Africa's biggest economy has posted tremendous growth in the service sector, boosted by rapid expansion in telecommunication and financial activity over the last decade, and now[when?] contributes 62% of GDP. 22% of GDP still comes from the unreliable agricultural sector which employs 75% of the labour force (a consistent characteristic of under-developed economies that have not attained food security – an important catalyst of economic growth) A small portion of the population relies on food aid.[citation needed] Industry and manufacturing is the smallest sector, accounting for 16% of GDP. The service, industry and manufacturing sectors only employ 25% of the labour force but contribute 75% of GDP.