Complex sentence: La Libertad region is the third most numerous in Peru, since in census 2007 the number of inhabitants was of 1,617,050 in that year representing 5.9% of the Peruvian population, surpassed only by the Department of Lima and Piura.
Split into simpler sentences: La Libertad region is the third-most populous in Peru; the census 2007 recorded 1,617,050 residents, representing 5.9% of the Peruvian population. It was surpassed only by the Department of Lima and Piura.