India is the second largest populated country in the world. India's share in the world population is 17.5%. The population of India, at 121 crore, is almost equal to combined population of USA, Indonesia, Brazil, Pakistan, Bangladesh and Japan. The year 1921 was referred as the year of 'Great Divide.' From 1921 onwards India's population started rising steadily. The average annual growth rate of population during this 30 years period increased to 1.22 percent. During the phase of 1951−1981, India witnessed population explosion. Growth rate of population reached to 2.2% by 1981 . Average annual growth rate of the population during this period reached to 2.15%.