But that is the point of the graph - to show the ratio of history that has happened has happened recently. Or in other words, the point is not to show the growth patterns, but to show the nominal value.
I think that's where it's wrong, though; imo, "history" is better identified with the percent change, not with the nominal value. If someone improved some technology by 10% in 1850, and someone else improved it by another 10% in 1950, I'd call those historically equivalent contributions.
