Suppose we have the following data:
begin date end date quantity
10/01/13 01/06/14 5
01/07/14 01/01/2015 7.5
01/02/2015 07/03/2015 10.67
The average difference between end dates is about 0.5 years. I want to project the future quantities using the average difference between end dates. I have something like the following:
begin date end date quantity
10/01/13 01/06/14 5
01/07/14 01/01/2015 7.5
01/02/2015 07/03/2015 10.67
07/04/2015 01/02/2016
01/03/2016 07/03/2016
07/04/2016 01/02/2017
01/03/2017 07/04/2017
The end dates were determined by adding 0.745 years (~182 days) to the start dates. Is there any good way of getting the four future projections for quantity?
Could I look at the percentage increase in quantity based on end dates:
$$ \frac{\frac{7.5-5}{5}}{\text{time between 01/06/14 and 01/01/2015}}$$ $$ \vdots $$
and somehow apply that?