Postgres 13

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CREATE TABLE data_table (id int, datetime timestamp, value numeric, type text, name text);
INSERT INTO data_table VALUES
(0,'2018-01-01 13:35:00+01:00',0.22,'HLN','NO2'),
(1,'2018-01-01 13:35:00+01:00',0.31,'HLN','CO'),
(2,'2018-01-01 13:35:00+01:00',1.15,'HLN','NO'),
(3,'2018-01-01 13:40:00+01:00',1.80,'AIS','NO2'),
(4,'2018-01-01 13:40:00+01:00',2.60,'AIS','CO'),
(5,'2018-01-01 13:40:00+01:00',2.30,'AIS','NO'),
(6,'2018-01-01 13:45:00+01:00',2.25,'HLN','NO2'),
(7,'2018-01-01 13:45:00+01:00',2.14,'HLN','CO'),
(8,'2018-01-01 13:45:00+01:00',2.96,'HLN','NO'),
(9,'2018-01-01 14:35:00+01:00',0.76,'HLN','NO2'),
(10,'2018-01-01 14:35:00+01:00',0.80,'HLN','CO'),
(11,'2018-01-01 14:35:00+01:00',1.19,'HLN','NO'),
(12,'2018-01-01 14:40:00+01:00',1.10,'AIS','NO2'),
(13,'2018-01-01 14:40:00+01:00',2.87,'AIS','CO'),
(14,'2018-01-01 14:40:00+01:00',2.80,'AIS','NO'),
(15,'2018-01-01 14:45:00+01:00',3.06,'HLN','NO2'),
(16,'2018-01-01 13:45:00+01:00',2.86,'HLN','CO'),
(17,'2018-01-01 13:45:00+01:00',2.22,'HLN','NO');

CREATE TABLE

INSERT 0 18

hour	type	name	avg
2018-01-01 13:00:00	HLN	CO	1.7700000000000000
2018-01-01 13:00:00	HLN	NO	2.1100000000000000
2018-01-01 13:00:00	HLN	NO2	1.23500000000000000000
2018-01-01 13:00:00	AIS	CO	2.6000000000000000
2018-01-01 13:00:00	AIS	NO	2.3000000000000000
2018-01-01 13:00:00	AIS	NO2	1.80000000000000000000
2018-01-01 14:00:00	HLN	CO	0.80000000000000000000
2018-01-01 14:00:00	HLN	NO	1.19000000000000000000
2018-01-01 14:00:00	HLN	NO2	1.9100000000000000
2018-01-01 14:00:00	AIS	CO	2.8700000000000000
2018-01-01 14:00:00	AIS	NO	2.8000000000000000
2018-01-01 14:00:00	AIS	NO2	1.10000000000000000000

SELECT 12