Calculate for how many years the simulation ran

Usage

simulation_time_to_years(simulation_time, pre_simulation_time, start_year)

Arguments

simulation_time: An integer. The number of periods (months) the simulation ran.
pre_simulation_time: An integer. The number of periods (months) the simulation ran before getting to a stable population. This is subtracted from 'simulation_time' in order to arrive at the "real" simulation time
start_year: An integer. The year the simulation started.

Value

A numeric scalar giving the calendar year reached at the end of the simulated period after subtracting pre_simulation_time / 12. The value can include a fractional year.