Complex sentence: San Andrés del Rabanedo has been one of the fastest growing towns; it increased its population by almost 24,000 people in the twentieth century and had gained another 4,000 by the year 2008.
Split into simpler sentences: San Andrés del Rabanedo has been one of the fastest growing areas. The town increased its population by almost 24,000 people in the twentieth century and had gained another 4,000 by the year 2008.