Kolkata one of the four major cities in India and situated on the bank of Ganga. The Municipal area of Kolkata is 185 Km2. and it consists of 145 wards including 4 wards under port area. The population of 145 wards according to 2001 census report is 45,80,544 (43,99,819 in 1991). The decadal growth of the population in last 10 years is 4.11%. The decadal growth of the population in the last 100 years is given below.