График частотности: math[b

[{"date": "2020-11-01", "qty": 3}, {"date": "2020-11-02", "qty": 3}, {"date": "2020-11-03", "qty": 3}, {"date": "2020-11-04", "qty": 3}, {"date": "2020-11-05", "qty": 3}, {"date": "2020-11-06", "qty": 3}, {"date": "2020-11-07", "qty": 3}, {"date": "2020-11-08", "qty": 3}, {"date": "2020-11-09", "qty": 3}, {"date": "2020-11-10", "qty": 3}, {"date": "2020-11-11", "qty": 3}, {"date": "2020-11-12", "qty": 3}, {"date": "2020-11-13", "qty": 3}, {"date": "2020-11-14", "qty": 3}, {"date": "2020-11-15", "qty": 3}, {"date": "2020-11-16", "qty": 3}, {"date": "2020-11-17", "qty": 3}, {"date": "2020-11-18", "qty": 3}, {"date": "2020-11-19", "qty": 3}, {"date": "2020-11-20", "qty": 3}, {"date": "2020-11-21", "qty": 3}, {"date": "2020-11-23", "qty": 3}, {"date": "2020-11-24", "qty": 3}, {"date": "2020-11-25", "qty": 3}, {"date": "2020-11-30", "qty": 3}, {"date": "2020-12-01", "qty": 3}, {"date": "2020-12-02", "qty": 3}, {"date": "2021-02-02", "qty": 3}, {"date": "2021-02-03", "qty": 3}, {"date": "2021-02-04", "qty": 3}]