d: Deaths
Variable
Population sector
Deaths [Person/year]
d = d1 + d2 + d3 + d4

d in the updating graph: ( how to read )
In nodes
d1 : deaths 0 to 14
d2 : deaths 15 to 44
d3 : deaths 45 to 64
d4 : deaths 65 plus
Out nodes
b : births
cdr : death rate