What is the total revenue of companies started by founder?
SELECT sum(revenue) ,  founder FROM manufacturers GROUP BY founder
SELECT sum(revenue) ,  founder FROM manufacturers GROUP BY founder
[{'sum(revenue)': 120.0, 'Founder': 'Andy'}, {'sum(revenue)': 50.0, 'Founder': 'James'}, {'sum(revenue)': 130.0, 'Founder': 'John'}, {'sum(revenue)': 200.0, 'Founder': 'Mary'}, {'sum(revenue)': 100.0, 'Founder': 'Owen'}, {'sum(revenue)': 30.0, 'Founder': 'Robert'}]