a and b – A single nativity (Italian) cluster with dates of each mortality. A more stringent clustering approach only included members from the same nativity while still using the same criteria of deaths being linked by distance and date range. Figure 5a displays one of the resulting clusters which still meets all of the previous cluster requirements, but for only Italian nativity mortalities. This original cluster now forms two sub-clusters (6a and 6b) due to the distance between Italian deaths, and the time frame between these deaths exceeding cluster requirements. Figure 5b considers just the sub cluster 6a, with the dates from all the Italian deaths added. At this scale, three further mortality groupings are evident. The buildings are graded in red according to their number of (all nativity) deaths.