The population of Japan is decreasing.

Demography is a part of social science that studies the structure, evolution, and problems of human population.

Demography is an important tool for understanding various aspects of society.

The next census will be conducted next year.

Demography is a branch of social science that studies the structure, distribution, and changes in human population.

Tokyo is the city with the highest population density in Japan.

Looking at the population pyramid, you can see that this country is aging.

I am very interested in social science.

Part of this movie is based on actual events.

He is an expert in sociology.