The data - which demonstrate the pressure the UK's ageing population is placing on an already-under pressure GP service - also reveal the wide variation in the GP:patient ratio across England, and wide disparities in numbers of patients aged over 65 per full-time equivalent (FTE) GP.
On average, there are 1,850 patients per FTE GP in England, analysis of the latest data on registered practice populations and GP workforce data from NHS Digital suggests.
But the GP:patient ratio varies widely between CCGs, from 2,442 patients per GP in NHS Swale, Kent, to 1,426 in NHS Redditch and Bromsgrove, in Worcestershire. Numbers of patients over 65 per FTE GP also vary widely, from 541 in NHS South West Lincolnshire to just 97 in NHS Tower Hamlets.
But some areas face the double whammy of high overall numbers of patients per FTE GP and higher than average numbers of patients aged over 65, suggesting that GPs in those areas are likely to face heavy workloads.
The findings also suggest that additional funding for practices with older populations via the GP funding formula has not translated into higher GP numbers in those areas.
NHS South West Lincolnshire, which has a higher proportion of patients aged over 65 per FTE GP than any other CCG in England, also has one of the highest numbers of patients per GP overall - with 2,426 patients per FTE GP.
Just over 22% of all patients registered with a GP in January 2017 were aged over 65 in NHS South West Lincolnshire, well above the national average of 17.5%. And the steady rise in numbers of older patients nationally means that over the past year, each FTE GP in the area gained an extra 11 patients over 65, the GPonline analysis suggests.
Each of the top three CCGs for numbers of patients over 65 per FTE GP have overall numbers of patients per FTE GP well above the national average - after NHS South West Lincolnshire, NHS Lincolnshire East and NHS South Kent Coast face the highest numbers of patients over 65 per FTE GP, with 524 and 510 respectively.
Both have overall numbers of patients per FTE GP above 2,000, with 2,038 in NHS Lincolnshire East and 2,215 in NHS South Kent Coast.
Further analysis of the GP registered populations data by GPonline revealed that the total number of practices counted in NHS Digital's latest data fell 181 from last year, highlighting the ongoing spate of practice closures across England.
GPC deputy chair Dr Richard Vautrey said the figures were 'yet more evidence of the crisis facing general practice right around the country'.
He said practice closures were 'a direct result of unsustainable and unsafe workload pressures, and failures to attract enough doctors in to general practice so that it's increasingly hard for practices to replace retiring GPs'.