Complex sentence: In 1991, the population of the Republic of Ireland was approximately 3% Protestant, but the figure was over 10% in 1891, indicating a fall of 70% in the relative Protestant population over the past century.
Split into simpler sentences: In 1991, the population of the Republic of Ireland was approximately 3% Protestant. The figure in the same geographical area was over 10% in 1891, indicating a fall of 70% in the relative Protestant population over the past century.