Complex sentence: As of 2014, the five BRICS countries represent almost 3 billion people which is 40% of the world population, with a combined nominal GDP of US $16.039 trillion (20% world GDP) and an estimated US $4 trillion in combined foreign reserves.
Split into simpler sentences: As of 2014, the five BRICS countries represent almost 3 billion people, or approximately 40% of the world population. The five nations have a combined nominal GDP of US $16.039 trillion, equivalent to approximately 20% of the gross world product, and an estimated US $4 trillion in combined foreign reserves.