Concatenate Year+Weeknum using dax

[Molin]

Dear experts, 

I am trying to create a dynamic column consistent of Year+"W"+Weeknum (e.g. 2021W10) which fits the Danish calendar system. However I am running into troubles around the last days of most years. 

The closest I have come is the following, which works between 18-19 and 19-20, however it creastes problems from year 2021 

YearWnum =

CONCATENATE(If(WEEKNUM(DateTable[Date],21)-WEEKNUM(DateTable[Date],2) <0,

DateTable[Year]+1,

DateTable[Year]),

DateTable[WeekNum])

Please note the week should start monday and some years have week 53 included (e.g. 2020)

Thanks in advance.