Total babies named Iwao (all years): 178
| Year | Boys (count / rank / %) |
|---|---|
| 1936 | 5 / #3793 / 0.000% |
| 1933 | 5 / #3896 / 0.001% |
| 1930 | 5 / #4264 / 0.000% |
| 1929 | 7 / #3390 / 0.001% |
| 1928 | 5 / #4431 / 0.000% |
| 1927 | 11 / #2615 / 0.001% |
| 1926 | 9 / #3019 / 0.001% |
| 1925 | 10 / #2843 / 0.001% |
| 1924 | 10 / #2922 / 0.001% |
| 1923 | 12 / #2520 / 0.001% |
| Year | Boys (count / rank / %) |
|---|---|
| 1922 | 11 / #2708 / 0.001% |
| 1921 | 20 / #1798 / 0.002% |
| 1920 | 14 / #2278 / 0.001% |
| 1919 | 9 / #2990 / 0.001% |
| 1918 | 13 / #2330 / 0.001% |
| 1917 | 13 / #2232 / 0.001% |
| 1916 | 9 / #2820 / 0.001% |
| 1915 | 5 / #4092 / 0.001% |
| 1914 | 5 / #3491 / 0.001% |