Complex sentence: Some 15,000 people were identified as residents in the 1950s, however, a growing number of reports regarding yōkai sightings and yōkai-related supernatural phenomena has led to a mass exodus.
Split into simpler sentences: Some 15,000 people were identified as residents in the 1950s,. However, a growing number of reports regarding yōkai sightings and yōkai-related supernatural phenomena has led to a mass exodus.