If I were to guess, the results lag behind the prevalence. It takes many years for someone to get cancer. If you were to push back the graph by 20 years it may

If I were to guess, the results lag behind the prevalence. It takes many years for someone to get cancer. If you were to push back the graph by 20 years it may correlate strongly. Edit: Also, the U.S. banned asbestos in 1989. That's the turning point of the graph.