Final answer:
Japan is expected to see the most significant increase in the percent of its population over age 65 among the listed countries, due to its high urbanization and low fertility rate.
Step-by-step explanation:
Among the given industrialized nations, Japan is expected to show the most dramatic increase in the percent of its population over age 65. High-income nations like Japan have a high degree of urbanization and a low fertility rate, which contributes to the aging population. Low-income and developing countries, such as India, typically have a younger population with high fertility rates. However, by around 2050, even the elderly populations in these countries are expected to increase significantly. Economic development, health insurance access, and cultural attitudes can all impact population demographics. Sweden is known for its liberal attitudes towards sex, while countries like Germany were pioneers in providing health insurance for workers. All these factors play a role in shaping the age distribution of a country's population.