The government's discriminatory pricing for the main cash crops, cotton and wheat, is apparently responsible for the exceptionally rapid growth of the cattle herd in recent years, as the prices of milk and meat, like those of fruits and vegetables, are also determined by market forces. The number of cattle increased from 4 million head in 1990 to 7 million head in 2006, and virtually all these animals are maintained by rural families with just 2-3 head per household. Sales of own-produced milk, meat, and vegetables in town markets are an important source for augmenting rural family incomes.