Census data for Sundby parish
| 1880 | 0 | 0 | 0 | 0.00% | 0 | 0.00% | 0 | 0.00% | |
| 1885 | 1,107 | 8,449 | 4,150 | 49.12% | 4,297 | 50.86% | 2 | 0.02% | 3,969 |
| 1890 | 0 | 0 | 0 | 0.00% | 0 | 0.00% | 0 | 0.00% | |
| 1895 | 1,940 | 9,489 | 4,461 | 47.01% | 4,546 | 47.91% | 482 | 5.08% | |
| 1901 | 3,064 | 16,725 | 8,238 | 49.26% | 8,484 | 50.73% | 3 | 0.02% | 0 |
| 1906 | 5,293 | 165 | 83 | 50.30% | 82 | 49.70% | 0 | 0.00% | 0 |
| 1911 | 6,174 | 15 | 10 | 66.67% | 5 | 33.33% | 0 | 0.00% | 0 |
| 1916 | 13,948 | 48 | 16 | 33.33% | 32 | 66.67% | 0 | 0.00% | 0 |
| 1921 | 6,335 | 160 | 70 | 43.75% | 81 | 50.63% | 9 | 5.63% | 0 |
| 1925 | 36,756 | 31 | 18 | 58.06% | 13 | 41.94% | 0 | 0.00% | 0 |
| 1930 | 35,969 | 955 | 474 | 49.63% | 481 | 50.37% | 0 | 0.00% | 0 |
| 1940 | 47,375 | 130 | 60 | 46.15% | 70 | 53.85% | 0 | 0.00% | 0 |