Getting Cumulative Sum if consecutive values in column

[worldCurrencies]

I have a dataframe that is like a time series. The first column has the date. then there are 5 other columns numbered 1-4, and grand total. It has the monthly change, but I am trying to get the cumulative sum of these monthly changes after it occurs consecutively. For example, in the picture, it is beginning by reporting returns in column 3. The total for those 3 rows are -0.56%. Then it starts column 4. Once it starts column 3 again, it will begin to sum cumulatively at 0 again. How would I do this?