Complex sentence: In 1805 there were only approximately 450 Catholics in the city, in 1814, when the number of communicants recorded was 3,000, the decision was taken to build a new church in Clyde Street.
Split into simpler sentences: In 1805 there were only approximately 450 Catholics in the city. By 1814, when the number of communicants recorded was 3,000, the decision was taken to build a new church in Clyde Street.