I don’t think back from 1900-1917 they could track every major quake that occurred.
Probably not all of them, but I would guess most of them could be tracked.
Even the Romans, Greeks, Chinese & Japanese tracked major earthquakes and dated them. It’s debatable whether these are accurate enough or not, but there are well documented major occurrences. Like the New Madrid Earthquakes of 1811-1812.
On the positive side, nobody, and I mean literally nobody dies from “consumption” in modern times.
I agree with DFW. the first seismograph was invented in 1880, https://www.britannica.com/science/seismograph
However, I will postulate that the seismographs of the last 50 years are more sensitive and are spread around the world in higher numbers than between 1900-1917. Thus we are detecting ‘more’ earthquakes and tremors than 100 years ago.
Think about the number of hurricanes that were reported in the 1800 or 1900s when those out at sea that developed and died without hitting land were unknown unless there was a ship in the area and it made it back to port to report the hurricane AND someone recorded it. Today we have satellites that cover the entire planet and they ‘see’ weather events that never are physically seen by people, but are still added to the number of that type of event, such as hurricanes.