prev month = if(CONTAINS(A,[client_type], "repeated"), CALCULATE(DIVIDE(CALCULATE(CALCULATE(COUNT(A[id])*'A'[% Repited_in_30_day],FILTER(A,'A'[client_type]="new")),DATEADD(A[Date_Overdue].[Date],-1,MONTH)),CALCULATE(count(A[id]),FILTER(A,'A'[client_type]="repeated")))),BLANK())