Instruction
It's time for a practice exercise. Are you ready?
Exercise
Find out how many aircraft PerfectAir launched each month. Prepare a report with the following informations:
- year (name the column
Year), - number of the month (name the column
Month), - number of aircraft launched this month (name the column
TotalAircraft).
Order the result by date: ascending year and descending month.
Stuck? Here's a hint!
First group and then order by year and the number of the month.



