Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Title | Author | Date | Length\n(first edition) |
| --- | --- | --- | --- |
| Bull-Dog Drummond | H. C. McNeile | 1920 | 320 pp |
| The Black Gang | H. C. McNeile | 1922 | 318 pp |
| The Third Round | H. C. McNeile | 1924 | 320 pp |
| The Final Count | H. C. McNeile | 1926 | 319 pp |
| The Female of the Species | H. C. McNeile | 1928 | 312 pp |
| Temple Tower | H. C. McNeile | 1929 | 320 pp |
| The Return of Bulldog Drummond | H. C. McNeile | 1932 | 316 pp |
| Knock-Out | H. C. McNeile | 1933 | 317 pp |
| Bulldog Drummond at Bay | H. C. McNeile | 1935 | 310 pp |
| Challenge | H. C. McNeile | 1937 | 311 pp |
| Bulldog Drummond on Dartmoor | Gerard Fairlie | 1938 | 254 pp |
| Bulldog Drummond Attacks | Gerard Fairlie | 1939 | 287 pp |
| Captain Bulldog Drummond | Gerard Fairlie | 1945 | 256 pp |
| Bulldog Drummond Stands Fast | Gerard Fairlie | 1947 | 319 pp |
| Hands Off Bulldog Drummond | Gerard Fairlie | 1949 | 271 pp |
| Calling Bulldog Drummond | Gerard Fairlie | 1951 | 255 pp |
| The Return of the Black Gang | Gerard Fairlie | 1954 | 192 pp |
| Deadlier Than the Male | Henry Reymond | 1967 | 192 pp |
| Some Girls Do | Henry Reymond | 1969 | 192 pp |
Question:
what year was the earliest bull-dog drummond published?
Answer:
1920