@moonbase isnt it just because south of watford is a much smaller area than north of in the UK?
the law of averages.
Population density favours south of Watford, however a genetically coded engineering aptitude is more prevalent north of Watford.
No averages, just DNA genetically disposed to DX north of Watford.
You could delve deeper into dish sizes and 36V motor use on a Watford north/south divide.
My guess is higher percentage of rubber band motor men south of Watford and more 36V men north of Watford.
Same guess on percentages for dishes of 1.8m and above that are installed and operational on a regular basis.
Data mining excercise for someone?