Population expression

[brucemeyers]

I want to create an expression that summarizes the previous year population of each country without having to manually enter the year (i.e. 2017) at the beginning of each new year.

I got this far but I need help

Sum({$<[Country]={Germany}>}[Population])

Pot 1	Year	Population
Russia	1/1/2018	143,964,709
Russia	1/1/2017	143,989,754
Russia	1/1/2016	143,964,513
Germany	1/1/2018	82,293,457
Germany	1/1/2017	82,114,224
Germany	1/1/2016	81,914,672
Brazil	1/1/2018	210,867,954
Brazil	1/1/2017	209,288,278
Brazil	1/1/2016	207,652,865
Portugal	1/1/2018	10,291,196
Portugal	1/1/2017	10,329,506
Portugal	1/1/2016	10,371,627
Argentina	1/1/2018	44,688,864
Argentina	1/1/2017	44,271,041
Argentina	1/1/2016	43,847,430
Belgium	1/1/2018	11,498,519
Belgium	1/1/2017	11,429,336
Belgium	1/1/2016	11,358,379
Poland	1/1/2018	38,104,832
Poland	1/1/2017	38,170,712
Poland	1/1/2016	38,224,410
France	1/1/2018	65,233,271
France	1/1/2017	64,979,548
France	1/1/2016	64,720,690

[felipedl · Accepted solution]

With your data, i did the following

load *,
Year(Year) as Num_Year;
load * Inline
[
Pot 1,Year,Population
Russia,1/1/2018,143964709
Russia,1/1/2017,143989754
Russia,1/1/2016,143964513
Germany,1/1/2018,82293457
Germany,1/1/2017,82114224
Germany,1/1/2016,81914672
Brazil,1/1/2018,210867954
Brazil,1/1/2017,209288278
Brazil,1/1/2016,207652865
Portugal,1/1/2018,10291196
Portugal,1/1/2017,11329506
Portugal,1/1/2016,12371627
Argentina,1/1/2018,44688864
Argentina,1/1/2017,44271041
Argentina,1/1/2016,43847430
Belgium,1/1/2018,11498519
Belgium,1/1/2017,11429336
Belgium,1/1/2016,11358379
Poland,1/1/2018,38104832
Poland,1/1/2017,38170712
Poland,1/1/2016,38224410
France,1/1/2018,65233271
France,1/1/2017,64979548
France,1/1/2016,64720690
];

And with the added field, I used it to get the current year for all selections and subtract one to get the last year.

sum
(
{<
Num_Year={"$(=Max(Total Num_Year)-1)"}
>}
Population
)

Getting: