fr: Food Ratio
Variable
Global
Food Ratio []
fr = fpci * fcm * fpm * clip ( fc , fc1 , swt7 ,time)/ fn

fr in the updating graph: ( how to read )
In nodes
fc : food coefficient ()
fc1 : food coefficient no. 1 ()
fcm : food-from-crowding multiplier
fn : food normal (food units/person/year)
fpci : food from capital investment
fpm : food-from-pollution multiplier
swt7 : switch time no. 7 for fc (years)
Out nodes
brfm : birth-rate-from-food multiplier
cfifr : capital fraction indicated by food ratio
drfm : death-rate-from-food multiplier
qlf : quality of life from food