with next_month as (
select
    strftime(date(max(MONTHLY), '+1 months')) as MONTHLY
from
    MRR_DATA
),mrr_base as (
    select
        MONTHLY,
        NEW_MRR + EXPANSION_MRR - DOWNGRADE_MRR - CHURN_MRR as MRR
    from
        MRR_DATA
    union all
    select
        MONTHLY,
        0 as MRR
    from
        next_month
)
select
    m1.MONTHLY as YM,
    m1.MRR + ifnull(m2.MRR,0) as MRR
from
    mrr_base as m1
left join
    mrr_base as m2
    on date(m1.MONTHLY) = date(m2.MONTHLY, '+1 months')
order by
    m1.MONTHLY