It has already been stated that there has been a decline in the percentage decadal growth rate (declined from 23.86 per cent during 1981-91 to 21.34 per cent during 1991-2001) and the average annual exponential growth rate (declined from 2.14 per cent during 1981- 91 to 1.93 per cent during 1991-2001) of the population growth of the country as a whole.
However, not all States and Union Territories have recorded a decline in their rates of population growth rates during 1991-2001.
It can be seen from where decadal percentage growth rates and average exponential growth rates during 1981-91 and 1991-2001 are presented for India, States and Union Territories, that, 26 States and Union Territories have experienced a decline in their population growth rates during 1991- 2001, eight states have experienced an increase in their rates of population growth.
During the decade of 1991-2001, the lowest decadal growth rate (9.42 per cent) and the lowest average annual exponential growth rate (0.90 per cent) were recorded by Kerala, followed by Tamil Nadu, Andhra Pradesh and Goa.
Highest decadal population growth rates are observed for Nagaland, and followed by Dadra and Nagar Haveli, Daman and Diu and Delhi.
While working out the density figures for Jammu and Kashmir for 1991 and 2001 censuses, the entire area and population of those portions of Jammu and Kashmir which are under illegal occupation of Pakistan and China have not been taken into account.
It is difficult to identify the factors responsible for inter-State variations in growth rates because reliable data on births, deaths and migration are not available.
Some explanation may, however, be sought in the socio-economic and political situations prevailing in the different States and Union Territories.
For instance, the higher growth rates of Assam, Tripura, Manipur and West Bengal during the decade 1961-1971 may be attributed to heavy immigration, not only from other parts of India, but also from Bangladesh.
On the other hand, the lower growth rates of Kerala and Punjab during the same decade as well as in the decade 1971- 1981 may be explained by their patterns of out-migration, not only to other parts of the country, but also to other countries.