Complex sentence: Of the roughly 150,000 people who die each day across the globe, about two thirds--100,000 per day--die of age-related causes; in industrialized nations, however, the proportion is much higher, reaching 90%.
Split into simpler sentences: Of the roughly 150,000 people who die each day across the globe, about two thirds--100,000 per day--die of age-related causes. In industrialized nations, the proportion is much higher, reaching 90%.