Fig 1. Bubble graph of 2020 cumulative incidence of COVID-19 in relation to 1974–2003 incidence of non-Hodgkin’s lymphoma in Sardinia, Italy.

A. all communes (N = 356), weighed (weigh = resident population); B. 61 residential units, including 25 communes with 10000 residents or more and 36 sub-regional areas incorporating the remaining 331 communes. Each commune is represented by a bubble of diameter proportional to its population size relative to the total regional population.