| Year | Population | Popn. per |
| | | sq. km |
|--------|-------------|-------------|
| 1991 | 5,102,400 | 66 |
| 1981 | 5,130,735 | 66 |
| 1971 | 5,228,963 | 68 |
| Year | Population | Popn. per |
| | | sq. mile |
|--------|-------------|-------------|
| 1961 | 5,179,344 | 174 |
| 1951 | 5,096,415 | 171 |
| 1931 | 4,842,980 | 163 |
| 1921 | 4,882,497 | 164 |
| 1911 | 4,760,904 | 160 |
| 1901 | 4,472,103 | 150 |
| 1891 | 4,025,647 | 135 |
| 1881 | 3,735,573 | 125 |
| 1871 | 3,360,018 | 113 |
| 1861 | 3,062,294 | 100 |
| 1851 | 2,888,742 | 97 |
| 1841 | 2,620,184 | 88 |
| 1831 | 2,364,386 | 79 |
| 1821 | 2,091,521 | 70 |
| 1811 | 1,805,864 | 60 |