monthly_revenue has one row per month (month is the first of the month, revenue the total). For every month that has a same month in the prior year, compute year-over-year growth.
Columns: month, revenue, prev_year_revenue, yoy_growth_pct (= 100 × (revenue − prev_year_revenue) / prev_year_revenue, rounded to 1 decimal). Only months whose prior-year counterpart exists appear. Sort by month.