Complex sentence: The island of Batam, which lies within the central core group of islands (the Riau Archipelago), contains a majority of the province's population; since becoming part of a Special Economic Zone with Singapore in 2006, it has experienced high population growth rates.
Split into simpler sentences: The island of Batam, which lies within the central core group of islands (the Riau Archipelago), contains a majority of the province's population. Since becoming part of a Special Economic Zone with Singapore in 2006, it has experienced high population growth rates.