I've been reading American government statistics from 1900-1930 and the term "Do" kept appearing in tables. Can someone explain to me what this term mean? The format is like this:
| Column 1 | Column 2 |
|---|---|
| Heading of the cases................................. | numbers |
| Specific case................................. | numbers |
| Do .................................. | numbers |
| Do .................................. | numbers |
Ditto.