Complex sentence: Globally coeliac disease affects between 1 in 100 and 1 in 170 people; rates do, however, vary between different regions of the world from as few as 1 in 300 to as many as 1 in 40.
Split into simpler sentences: Globally coeliac disease affects between 1 in 100 and 1 in 170 people. Rates vary between different regions of the world from as few as 1 in 300 to as many as 1 in 40.