Its a key question that you've raised @NotN0wBernard.
These are the highest and lowest English Council areas, excluding any in London.
Within the lowest group are a number of cities and towns that would have a far more diverse aged 50+population; so the likes of Nottingham, Slough, Luton, Leicester, Birmingham. But then also Oxford and Cambridge, Milton Keynes, Peterborough, Watford and Corby which - and happy to stand corrected - are probably relatively less so.
The highest group much more rural and likely much less diverse; a number also some of the least deprived council areas, but by no means all fit into this.
Although thinking about some of the wealthiest parts of the country - only a couple of council areas in the South East make that very highest take up list.