highly significantP < 1 × 10 −15
As previously noted, a larger proportion of pairs have a TMRCA under 8 months in Sheffield relative to London (24% versus 4%), and overall the London pairs have an average TMRCA of 4.4 years compared to 1.5 years for the Sheffield pairs, with the difference being highly significant (KWT, P < 1 × 10 −15 ).