With 34 songs dropping out of the Top 75 this week – all but two of them Christmas-related – the singles chart is extremely volatile... but not at the top, where Ed Sheeran's Perfect spends its fifth week at No.1.

Combining paid-for sales (20,362) and sales-equivalent streams (36,673) of Sheeran's original album version and duet versions with Beyoncé and Andrea Bocelli, Perfect had a combined tally of 57,035 sales in the week, the smallest of its reign.

Perfect may be ...