The major change in agriculture in Kerala occurred in the 1970s when production of rice fell due to increased availability of rice all over India and decreased availability of labour.[142] Consequently, investment in rice production decreased and a major portion of the land shifted to the cultivation of perennial tree crops and seasonal crops.[143][144] Profitability of crops fell due to a shortage of farm labour, the high price of land, and the uneconomic size of operational holdings.[145] Only 27.3% of the families in Kerala depend upon agriculture for their livelihood, which is also the least curresponding rate in India.[146]