График частотности: объяснений

[{"date": "2011-06-04", "qty": 3}, {"date": "2011-07-21", "qty": 3}, {"date": "2011-12-09", "qty": 3}, {"date": "2012-06-08", "qty": 3}, {"date": "2013-05-19", "qty": 6}, {"date": "2013-06-17", "qty": 3}, {"date": "2013-06-30", "qty": 3}, {"date": "2013-10-10", "qty": 3}, {"date": "2013-11-28", "qty": 7}, {"date": "2015-01-29", "qty": 4}, {"date": "2017-12-16", "qty": 4}, {"date": "2018-01-10", "qty": 3}, {"date": "2018-01-12", "qty": 5}, {"date": "2019-05-28", "qty": 4}, {"date": "2019-06-01", "qty": 3}, {"date": "2020-04-19", "qty": 3}, {"date": "2024-05-25", "qty": 4}, {"date": "2024-05-26", "qty": 3}, {"date": "2024-05-27", "qty": 3}, {"date": "2025-09-16", "qty": 3}]