MATHEMATICS

	In the previous chapter we saw that the scientific method on which life assurance is based started with James Dodson's mortality table. His mortality table showed the number of deaths that could be expected every year at every age level. In fact with a little revision this phrase defines what we mean when we talk about "mortality", namely, the number of deaths in a given period.
	Dodson created this table because in 1756 he was refused entry to John Hartley's scheme because at 46 he was too old.
	Over the years mortality statistics have become more and more accurate. As well as long term statistics compiled for the population at large, assurance companies have kept specialised statistics of the population at large, assurance companies have kept specialised statistics of the insured population; that is those people who have, over the years, insured their lives. With the improvement of social conditions and medical knowledge people are now living longer.
	A scientific basis for conducting life assurance was developed. His refusal prompted him to devise a new method for calculating the premium to be paid for life assurance. By visiting graveyards he compiled a table showing the numbers of people who died at each age between the years 1756 and 1759. Using this, the first mortality table, using compound interest and probability he calculated a premium for each age, which would remain fixed for a 'level premium'.