Lesotho is geographically surrounded by South Africa and economically integrated with it. The economy of Lesotho is based on agriculture, livestock, manufacturing and mining, and depends heavily on inflows of workers' remittances and receipts from the Southern African Customs Union (SACU). The majority of households subsist on farming. The formal sector employment consists mainly of female workers in the apparel sector, male migrant labour, primarily miners in South Africa for three to nine months, and employment by the Government of Lesotho (GOL). The western lowlands form the main agricultural zone. Almost 50 percent of the population earn income through informal crop cultivation or animal husbandry with nearly two-thirds of the country's income coming from the agricultural sector. The percentage of the population living below USD Purchasing Power Parity (PPP) US$1.25/day fell from 48 percent to 44 percent between 1995 and 2003. The country is among the "Low Human Development" countries (rank 160 of 187 on the Human Development Index as classified by the UNDP, with 52 years of life expectancy at birth. Adult literacy is as high as 82 percent. Among the children below the age of five years, 20 percent are under weight.