| Census Year | Population | Difference of Population from Preceeding Census | Difference in Percent |
| 1981 | 320,861 | 68,547 | 27.17 |
| 1991 | 480,520 | 159,659 | 49.76 |
| 2001 | 669,087 | 188,567 | 39.24 |
| 2011 | 872,575 | 209,488 | 31.30 |