Since the city of Toyota, Aichi Prefecture, merged with six towns and villages 10 years ago, the population has grown by 3.4 percent to more than 421,000 people.

However, the data also reveal that while the population in what was formerly Toyota has grown 4.6 percent, the number of people living in the other six towns and villages has declined by 6.1 percent.

The gap between the number of people living in the city and in the country — a key concern before the merger — has only widened.