t	a1	a2
20-09-2020 12:00:40	NA	43
20-09-2020 12:38:56	28	NA
20-09-2020 14:00:40	NA	44
20-09-2020 14:02:40	NA	45
20-09-2020 14:08:34	22	NA
20-09-2020 14:10:41	20	NA
20-09-2020 16:31:11	22	NA
20-09-2020 16:31:25	24	NA
20-09-2020 23:55:40	NA	46
21-09-2020 03:55:40	NA	47
21-09-2020 03:00:00	30	60