Complex sentence: In the Faroe Islands, Greenland and Iceland, natural population increase had the greatest impact on the population change, but both Greenland and the Faroe Islands still had a slight decrease in the population due to a negative net migration in 2012.
Split into simpler sentences: In the Faroe Islands, Greenland and Iceland, natural population increase had the greatest impact on the population change. But both Greenland and the Faroe Islands still had a slight decrease in the population due to a negative net migration in 2012.