Complex sentence: The Fab 40 had a significantly higher turnover of singles than the "Record Retailer" chart; it had 118 different singles top the chart between 23 January 1965 and 12 August 1967 (by comparison "Record Retailer" had 53).
Split into simpler sentences: The Fab 40 had a significantly higher turnover of singles than the "Record Retailer" chart. It had 118 different singles top the chart between 23 January 1965 and 12 August 1967 (by comparison "Record Retailer" had 53).