Regional differences and changes in choice for location of practise and density of family doctors in the period of 1969 until 1979. registered items per region in 1969 and in 1979: population figure / percentage of population growth in the last 10 years / migration / natural growth / percentage aged people and children of 0-4 years old / birth rate / average income / percentage of people covered by Dutch National Health Service / indication of number of accoucheurs and pharmacies / index urbanisation / hospital / final examination in medicines of 6 universities / number of establishments / number of family doctors ( in age categories ) / mean of age of family doctors / density of family doctors.