Beast Mode Cumulative Sum Calculation for given scenario

You can use windowed functions (talk to your CSM to get them enabled if you don't have them in your instance).

I'm basing these on your example document but if you're wanting to see the running total you'd want to change OVER () to OVER (ORDER BY `Year`)

- Cumulative Amount Current Year-2020

SUM(CASE WHEN YEAR(CURDATE()) - `Year` = 0 THEN `Total` ELSE 0 END) OVER ()

- Cumulative Amount PreviousYear-2019

SUM(CASE WHEN YEAR(CURDATE()) - `Year` = 1 THEN `Total` ELSE 0 END) OVER ()

- Cumulative Amount for last 5 Years-(2015-2010)

SUM(CASE WHEN YEAR(CURDATE()) - `Year` <= 5 THEN `Total` ELSE 0 END) OVER ()

- Cumulative Amount Lifetime

SUM(`Total`) OVER ()

If you don't need to show the individual years you can do it without windowing functions and just itilize the CASE statements in each beast mode and drop the OVER () windowing function.