Digging more into history and found these. I assume that first 5 are not possible to find out? Or maybe that OH-JA? Jetstream somehow? But how about ones from 2005? What could be the source?

4.2.1990 AY 1541 HEL 7:25 ACE 11:55
11.2.1990 AY 1542 ACE 12:55 HEL 21:15
15.5.1997 KF 565 LPP 13:55 HEL 14:35 Based on photo this is one of OH-JA? BAe Jetstreams that Air Botnia had
15.5.1997 AY 233 HEL 14:55 TKU 15:30
9.3.2000 LH 3014 FRA 13:40 HEL 17:00
2.3.2005 AY 651 HEL 7:35 OSL 8:10
2.3.2005 AY 658 OSL 19:10 HEL 21:35
17.5.2005 AY 655 HEL 11:00 OSL 12:30
17.5.2005 SK 352 OSL 14:40 TRD 15:35
18.5.2005 SK 373 TRD 17:40 OSL 18:30
18.5.2005 SK 1488 OSL 21:15 ARN 22:15
18.5.2005 KF 434 ARN 22:45 HEL 0:35
29.5.2005 SU 436 AY 153 HEL 9:25 SVO 12:05
31.5.2005 SU 435 AY 154 SVO 12:50 HEL 13:40
29.8.2005 AY 773 HEL 16:30 VCE 18:15
5.9.2005 AY 774 VCE 19:00 HEL 22:45
4.10.2005 LH 3105 HEL 9:00 FRA 10:20
4.10.2005 LH 778 FRA 22:30 BKK 15:55
7.10.2005 LH 773 BKK 23:00 MUC 6:10
8.10.2005 LH 3110 MUC 8:55 HEL 12:20
10.11.2005 SK 701 HEL 6:25 ARN 6:15
10.11.2005 SK 3031 ARN 7:10 DUS 9:00
10.11.2005 SK 1622 DUS 16:10 CPH 17:30
10.11.2005 SK 714 CPH 19:45 HEL 22:15
23.11.2005 AY 703 HEL 7:20 DUS 8:40
23.11.2005 AY 708 DUS 18:25 HEL 21:45