with wk as (
    select
        DATE(MONTHLY, '+1 month') AS MONTHLY
    from MRR_DATA
)
select
    COALESCE(wk.MONTHLY, m.MONTHLY) AS YM,
    COALESCE(SUM(NEW_MRR) OVER (ORDER BY wk.MONTHLY ROWS BETWEEN UNBOUNDED PRECEDING AND 1 PRECEDING), 0)
    + COALESCE(SUM(EXPANSION_MRR) OVER (ORDER BY wk.MONTHLY ROWS BETWEEN UNBOUNDED PRECEDING AND 1 PRECEDING), 0)
    - COALESCE(SUM(DOWNGRADE_MRR) OVER (ORDER BY wk.MONTHLY ROWS BETWEEN UNBOUNDED PRECEDING AND 1 PRECEDING), 0)
    - COALESCE(SUM(CHURN_MRR) OVER (ORDER BY wk.MONTHLY ROWS BETWEEN UNBOUNDED PRECEDING AND 1 PRECEDING), 0)
    AS MRR
from wk
full join MRR_DATA m
on wk.MONTHLY = m.MONTHLY
order by YM