Worst Delay per Route

For every route return the maximum delay in days. Order by max_delay descending, then route.

Table schema

Shipments(id INT PRIMARY KEY, route VARCHAR(10), delay_days INT)

Sample data

id | route | delay_days
1 | R1 | 2
2 | R1 | 5
3 | R2 | 0
4 | R2 | 3
5 | R3 | 5