Through Table Cals I was able to get forecast based upon your ship data, but the thing is it says forecast can't be computed as there are fewer values rather than what are required for forecasting. Have a look at attached and screenshot and try to apply to your data.
Fcst Review Sample data 9.3.twbx 164.1 KB
Thanks for the reply, Deepak.
I had the same issue too, so I want to perform a manual calculation i.e Q2 17=(Q1 17)*(Sum(Q2 16)/Sum(Q1 16)) and so on for the rest.
To do that I'd have to either perform a calculation on the pivoted fields or pivot a calculated field, both of which I cannot seem to do on Tableau.