Complex sentence: Between 1971 and 1991, mortality from heart disease dropped 41 percent, strokes decreased by 59 percent, and today more than 70 percent of children who get cancer are cured.
Split into simpler sentences: Between 1971 and 1991, mortality from heart disease dropped 41 percent, strokes decreased by 59 percent. And today more than 70 percent of children who get cancer are cured.