График частотности: калви

[{"date": "2019-02-18", "qty": 11}, {"date": "2019-02-19", "qty": 3}, {"date": "2019-02-20", "qty": 9}, {"date": "2019-02-21", "qty": 4}, {"date": "2019-02-25", "qty": 7}, {"date": "2019-02-26", "qty": 5}, {"date": "2019-02-27", "qty": 3}, {"date": "2019-02-28", "qty": 5}, {"date": "2019-03-12", "qty": 11}, {"date": "2019-03-13", "qty": 5}, {"date": "2019-03-14", "qty": 4}, {"date": "2019-03-15", "qty": 7}, {"date": "2019-03-16", "qty": 4}, {"date": "2019-03-17", "qty": 4}, {"date": "2019-03-18", "qty": 4}, {"date": "2019-03-19", "qty": 4}, {"date": "2019-03-20", "qty": 3}, {"date": "2019-04-10", "qty": 4}, {"date": "2019-04-11", "qty": 11}, {"date": "2019-06-03", "qty": 3}, {"date": "2019-06-07", "qty": 8}, {"date": "2019-06-08", "qty": 13}, {"date": "2019-06-09", "qty": 4}, {"date": "2019-10-08", "qty": 4}, {"date": "2019-12-23", "qty": 3}, {"date": "2020-02-12", "qty": 5}, {"date": "2021-01-22", "qty": 3}]