График частотности: x[]+b[]

[{"date": "2019-11-12", "qty": 3}, {"date": "2019-11-15", "qty": 17}, {"date": "2019-11-16", "qty": 14}, {"date": "2019-11-17", "qty": 11}, {"date": "2019-11-19", "qty": 19}, {"date": "2019-11-21", "qty": 10}]