The physical area of Pakistan is equivalent to the US states of Texas and Louisiana combined. Much of Pakistan’s land area comprises either deserts or mountains. The high Himalayan ranges border Pakistan to the north. The lack of rainfall in the western part of the country restricts agricultural production in the mountain valleys and near the river basins. Approximately 64 percent of the population lives in rural areas and makes a living in agriculture. Most of the people are economically quite poor by world standards. In spite of the rural nature of the population, the average family size has decreased from seven to four in recent decades. Nevertheless, the population has exploded from about 34 million in 1951 to about 187 million as of 2011. About half of the population is under the age of twenty; 35 percent is under the age of fifteen. A lack of adequate medical care, an absence of family planning, and the low status of women have created an ever-increasing population, which will have dire consequences for the future of Pakistan. Service and infrastructure to address the needs of this youthful population are not available to the necessary degree. Schools and educational opportunities for children are rarely funded at the needed levels. As of 2010, only about 50 percent of Pakistan’s population was literate.