Running Total - DAX

Thanks for your contribution,

Unfortunately I`m still stuck with the issue, I try to better describe the complexity of the issue here, I have two comparable sets of date adjusted dates belonging to 2017 and to 2018, the main issue is to obtain a calculated column which can give me the running total in 2017 and then start back from zero and calculate the running total in 2018, I presume a conditional statement which filters out the relevant dates from the sum would be necessary. in the screenshot an example where the dates are passing from 2017 into 2018 and it`s there that the running total needs to stop and start back from zero.

Thanks again for your time