with MAX as (
	select 
		max(MONTHLY) maxmon
	from
		MRR_DATA
),S as (
	select min(MONTHLY) as YM, 0 as MRR from MRR_DATA
	union all
	select
		date(YM, '+1 months') as YM,
		S.MRR + 
		(select 
			M.NEW_MRR + M.EXPANSION_MRR - M.DOWNGRADE_MRR - M.CHURN_MRR
		from
			MRR_DATA M
		where
			M.MONTHLY = S.YM
		)
	from
		S
	where
		S.YM < date((select maxmon from MAX), '+1 months')
)

select * from S
order by YM asc