График частотности: болтона

[{"date": "2012-04-16", "qty": 3}, {"date": "2018-06-27", "qty": 10}, {"date": "2018-10-22", "qty": 3}, {"date": "2019-01-29", "qty": 4}, {"date": "2019-09-10", "qty": 11}, {"date": "2019-09-11", "qty": 5}]