Complex sentence: At the end of the 20th century, the population of the Philippines has increased rapidly to 75.32 million in a country of 297,410 square kilometers, with an average family size of six, making the Philippines known for high population density.
Split into simpler sentences: At the end of the 20th century, the population of the Philippines has increased rapidly to 75.32 million. This means that each family is comprised of 6 persons while living in a country of 297,410 square kilometers thus making the Philippines known for having a very high population density.