with recursive cte as (
  select
    MONTHLY as YM,
    0 as MRR,
    0 + NEW_MRR + EXPANSION_MRR - DOWNGRADE_MRR - CHURN_MRR as next
  from MRR_DATA
  where MONTHLY = (select min(MONTHLY) from MRR_DATA)
  union all
  select
    MONTHLY,
    cte.next,
    cte.next + NEW_MRR + EXPANSION_MRR - DOWNGRADE_MRR - CHURN_MRR
  from cte inner join MRR_DATA on MONTHLY = date(cte.YM, '+1 months')
)
select YM, MRR from cte