select
    m_1.monthly as YM,
    -- m_2.monthly as m_2_monthly,
    -- substring(m_1.monthly, 6, 2) as month,
    -- cast(substring(m_1.monthly, 6, 2) as integer) as month_int
    case
        when m_1.monthly != '2022-01-01' then
            m_2.new_mrr + m_2.expansion_mrr - m_2.downgrade_mrr - m_2.churn_mrr
        else 0
    end as MRR
from mrr_data as m_1
left outer join mrr_data as m_2
on
  cast(substring(m_1.monthly, 6, 2) as integer) = cast(substring(m_2.monthly, 6, 2) as integer) + 1
order by
    YM 
;