Chandigarh was planned for a population of half-a-million. In Phase I, 36 sq km of land was acquired by the city administration for construction of 30 sectors. Land for seventeen additional sectors (Sector 31 to 47) was acquired and developed during the second phase to cater for a population of 350,000. The predominance of ¾ storey apartments in the second phase provide for higher population dimension. However, Chandigarh has now grown beyond its planned capacity. Hence, development in the third phase has started in sectors 48 and beyond. Demographic data indicate that between 1961 and 1971, the population increased by 144.59 percent, one of the highest for urban areas in India. According to 1981 census, it grew by another 75.55 percent, followed by 42.16 percent in 1991 and by 40.33 per cent in 2001 (with a total population of 9,00,635). By 2021 the population of Chandigarh is projected to be around 19.5 lacs (at current rate of growth) almost four times for which it was originally built.