Thanks I had no idea death rates and disease incidence were distinct data points.
No problem.
It isn't something that you think about at first. You just see the graph and it looks "right". But then when you think of the immense advances in basic medical care that occurred around the turn of the last century (punctuated by the First World War), you can see that it makes sense that more sick people are given the chance to pull through with the proper support.