SQL divide row by row with the same column by using CASE

I want to create a new column which is to calculate the percentage, I know it can use subquery to do that,

but is it possible to use CASE to do this? If using CASE how is the logic?

Column A	Column B	Column C	New Column that i want to create
2022-01-01	M0	72	72 * 100 / 72
2022-01-01	M1	53	53 * 100 / 72
2022-01-01	M2	29	29 * 100 / 72
2022-01-01	M3	18	18 * 100 / 72
2022-01-01	M4	2	2 * 100 / 72
2022-01-02	M0	102	102 * 100 / 102
2022-01-02	M1	80	80 * 100 / 102
2022-01-02	M2	72	72 * 100 / 102
2022-01-02	M0	32	32 * 100 / 102
2022-01-02	M0	14	14 * 100 / 102
…
…
…

Answer

Try this:

SELECT T1.colC * 100 /T2.colC
FROM Table1 T1
INNER JOIN Table1 T2 
ON T1.colA = T2.colA
AND T2.ColB = 'M0'