Complex sentence: This makes it difficult to accurately record the demographics of LGBT community in the U.S. Though, studies from various nations, including the U.S., covering varying time periods and age groupings have produced a consistent range 1.20--5.60% of the adult population.
Split into simpler sentences: This makes it difficult to accurately record the demographics of LGBT community in the United Sates. Studies from various nations, however, including the U.S., covering varying time periods and age groupings, have produced a consistent statistical range of 1.20--5.60% of the adult population.